Mario in this game has changed from a plucky plumber to a determined doctor who has to destroy all of the viruses (red, yellow and blue ones, with green and purple viruses introduced in Dr. Mario World). He uses a series of capsules to eliminate them (when four capsule pieces/viruses of the same color line up in a row).

Dr. Mario proved just as addictive as its puzzle game parent. "Fever" and "Chill", the game's two main themes, are almost as iconic as "Korobeiniki". Two other tunes, "Cough" and "Sneeze", have also been present since the N64 iteration.

Games in the series:

• Dr. Mario (Nintendo Entertainment System and Game Boy)
• Tetris & Dr. Mario (Super Nintendo Entertainment System, Updated Compilation Re-release)
  • BS Dr. Mario (Satellaview, standalone release of the Dr. Mario remake contained in the above. Later released as a download for the Super Famicom's "Nintendo Power" service).
• Dr. Mario 64 (Nintendo 64, featuring characters from Wario Land 3 as opponents, notable for being the only time Wario characters appear in the extended Mario universe)
• Nintendo Puzzle Collection (Nintendo GameCube, a Japan-only Compilation Re-release of Dr. Mario 64, Yoshi's Cookie, and Panel de Pon)
• Dr. Mario & Puzzle League (Game Boy Advance, Updated Compilation Re-release)
• Dr. Mario Online RX (WiiWare)
• Dr. Mario Express (Nintendo DSiWare)
• Dr. Luigi (Wii U, a Mission-Pack Sequel to Dr. Mario Online RX which celebrates The Year of Luigi by replacing Mario with Luigi and introducing the "Operation L" mode)
• Dr. Mario: Miracle Cure (Nintendo 3DS, which introduces power ups to the series and features Dr. Mario and Dr. Luigi together for the first time)
• Dr. Mario World (iOS Games and Android Games)

Other appearances:

• The game made an appearance as a minigame in both WarioWare Inc.: Mega Microgame$ ("Dr. Wario", which is pretty much a sprite swap of the NES version) and Brain Age ("Virus Buster", which introduced touch controls to the series).
• Dr. Mario is a recurring fighter in Super Smash Bros. as a Moveset Clone of the regular Mario, appearing in Melee, the Nintendo 3DS and Wii U games, and Ultimate.
• The viruses appear as enemies in Mario & Luigi: Superstar Saga and Mario & Luigi: Dream Team.
• Dr. Mario appears in the Mario Kart series twice as a variant of Mario in Mario Kart Live: Home Circuit and Mario Kart Tour.
• The ending credits of The Super Mario Bros. Movie include an orchestrated medley of various Mario franchise tracks, including "Fever".

Dr. Mario contains examples of:

• Adaptational Job Change: Dr. Mario World changes Peach from a nurse to a doctor.
• Ascended Extra:
  • In most media outside the game, the Viruses are given their own powers and personalities relating to the sickness they instill. Two of them are also named after the tunes in the game, the other one being "Weird", the Yellow Virus. In the games, they're simply obstacles.
  • Whilst Princess Peach made prior appearances in artwork as a nurse, Dr. Mario World not only has her appear in-game but also upgrades her to a full-fledged doctor.
  • Also from Dr. Mario World, while they've both previously been an enemy and an ally respectively, them being Doctors here marks the first time Goomba Tower and Dolphin have ever been Playable in the entire Mario franchise.
• Back-Alley Doctor: Miyamoto has suggested that Mario is not exactly a legitimate doctor.
• Bacteria Devil: The viruses are designed as small and round blobs with little rounded horns. Their original Western designs made them much more devil-like, with grimacing faces and much longer curved horns. Newer viruses are given subtly less devil-like designs, but still keep the similar vein.
• Bat Family Crossover: Notably, Dr. Mario 64 is the only time that Mario's interacted with anyone introduced in Wario's games (specifically, characters from Wario Land 3).
• Bookends: In 64's story mode, your rival can be fought twice- once at the beginning of the game, and again as the True Final Boss in Hard mode.
• The Bus Came Back: Update 1.05 of Dr. Mario World brought back Wario as an unlockable playable character, 18 years after 64. His outfit, however, is redesigned 16 years after Mega Microgame$. On a related and perhaps truer example, Baby Wario was added in for Season 3 on June 26, 2020, after not making a single appearance in the entire Mario franchise since Yoshi's Island DS back in 2006, 14 years prior.
• Butt-Monkey: The red virus in the "Virus Vids" made to promote Dr. Mario World. He disappears due to a red pill in eight of them.
• Color-Coded for Your Convenience: It's a color-match puzzler, so...
• Comic-Book Adaptation: "The Doctor Is In... Over His Head" from the Nintendo Comics System explains to us how Mario got to be a doctor.
• Continuity Nod: Not necessarily in this game, but all three viruses have been featured as enemies in the Mario and Luigi series.
  • In Superstar Saga they change into different viruses, and are taken out all at once when matched up. In addition, they also power up another enemy called an Eeker.
  • In Bowser's Inside Story a Blue Virus is spat up by Toothies as an attack. They stab Bowser with a spear if they reach him in time.
  • Dream Team has them as enemies again, with the same matching color gimmick, except this time they always come in a 4-by-4 group of 16 and the matching colors have to be next to each other to get a match kill.
• Critical Annoyance: The game plays an ambulance siren whenever you get within three spaces of topping out. What makes this really fall under the "annoyance" part of this trope is that the later levels' viruses are already crowded up to that position, which means you'll be hearing the siren approximately every 15 seconds and likely yelling at the game for this.
• Dressed to Heal: The lab coat makes sense, but there's no reason other than this trope for Dr. Mario, who appears to work in pharmaceuticals, to wear a mirror and stethoscope.
• Easy-Mode Mockery: In Dr. Mario 64, when playing Round 7 in Easy Mode, it's just you and the Hammer-Bot from Wario Land 3. But in higher difficulties, it's a free-for-all between the aforementioned, your rival, and Mad Scienstein. You also can't face the True Final Bosses in Easy Mode. Interestingly, Easy Mode also creates a case of What Happened to the Mouse? when playing as Wario — in the opening for the final round, Dr. Mario is seen entering the castle after Wario, but doesn't show up again after that. In the higher difficulties, however, Dr. Mario just sits there dazed from the free-for-all battle as Wario enters the castle without him.
• Enemy Mine: In Dr. Mario World, the viruses wreak havoc across the Mushroom Kingdom, including Bowser's minions. This leads to Bowser (and later, Wario and Waluigi) teaming up with Mario and Peach, explaining his role as a doctor in the game.
• Falling Blocks: Well, falling pills.
• Given Name Reveal: The final boss of Wario Land 3 was never named in his debut. The English localization of Dr. Mario 64 names him "Rudy".
• Hero Antagonist: If you play as Wario in the N64 story mode, Dr. Mario is an opponent twice (three times if you count the aforementioned free-for-all). Once as your first opponent and as the True Final Boss on Hard mode.
• Hospital Hottie: As seen in the manual for the game, Princess Peach is a nurse at whatever clinic Mario oversees. Daisy and Rosalina join in come Dr. Mario World.
• An Ice Person: Chill, the Blue virus.
• Kill Screen: The Game Boy version can randomly cease functioning in the higher levels. In the low 20s, it starts to be possible for viruses to be laid out in ways that make it impossible to clear them, and in the high 20s there begins to be a chance that the game abruptly hangs partway through spawning viruses, leaving you just staring at a bottle full of viruses.
• Mercy Mode: In Dr. Mario World, failing a stage several times will cause Toad to give you a free bonus.
• Minus World: Resetting the NES Version has a tendency to corrupt ram values responsible for tracking the speed and virus level, leading to invalid virus arrangements, some of which spawn viruses at the top of the bottle where the pills fall in from.
• Monstrous Germs:
  • The ever-present trio of viruses are blue, red and yellow Cephalothorax creatures with eyes, mouth, hands and feet.
  • There's also the "B-Strain" in cyan, magenta, and yellow that menace Dr. Luigi. ^note Er... "menace". In the cutscenes, they're treated as Friendly Enemies more than anything.
• Oh, Crap!: The Viruses in Miracle Cure get this expression when their respectively-colored Virus Buster appears in play. All three do this simultaneously when a Zapper or Exploder appears. When there is only one color of virus left in play in Classic mode, it starts to panic.
• One-Winged Angel: In 64, Wario turns into a vampire after glomming on some Megavitamins. Dr. Mario turns metal instead.
• Overflow Error: Clearing a sufficiently large combo in the NES version will break past the end of the scoring table, resulting in the game trying to give hundreds of times more points than normal — key word "trying", because the calculation for this takes far longer than normal, resulting in the controller-polling code interrupting unexpectedly and probably softlocking the game, though a TAS can use the controller 2 input to insta-clear all viruses instead.
• Pink Means Feminine: While the viruses don't really have genders per se, the magenta virus of the B-Strain has prominent eyelashes and a high-pitched, "girly" voice.
• Public Domain Soundtrack:
  • The first five notes of The Flea Waltz (known in Japanese as "Neko Funjatta"^note "I stepped on a Cat") can be heard in some versions when Mario accomplishes certain feats, such as making combos or attacking the other player.^note That is, sending the other player "garbage" capsules.
  • The Game Boy and SNES version use the first seven notes of "Ach du Lieber Augustin" for combos.
• Recycled Soundtrack: In regards to the "Virus Buster" game mode, Online Rx averts this by creating brand new arrangements of "Fever" and "Chill". Dr. Luigi and Miracle Cure, on the other hand, play this straight by straight-up reusing the original Brain Age 2 arrangements.
• Shrunken Head: A commercial had a guy telling how he beat a witch doctor at the game, and got his head shrunk as a result.
• Songs in the Key of Panic: 64 plays the classic warning tune from Super Mario Bros. 1 and speeds up the music when either player has only three viruses left in their bottle, warning the other player that they don't have much time left to try to catch up. Strangely, this is also present in the single-player Classic mode.
• Totem Pole Trench: Dr. Goomba Tower from Dr. Mario World is a tower of three Goombas with a lab coat draped over it. The lab coat is wide open, so they're not even trying to pretend that they are a single six-foot tall Goomba.
• True Final Boss: Dr. Mario 64 has two. If you beat the game as either character, you face his rival, who has just ingested the megavitamins, resulting in either Metal (Dr.) Mario or Vampire Wario.