In this comic episode, the starship Enterprise visits a space station that soon becomes overwhelmed by rapidly reproducing small furry creatures called "tribbles".

The first, "More Tribbles, More Troubles", was originally pitched for the show's third season but not accepted;[3][4] it was ultimately produced for Star Trek: The Animated Series.

The Enterprise is summoned to Deep Space Station K7 by undersecretary Nilz Baris to guard a shipment of quadrotriticale grain.

Captain James Kirk is annoyed at Baris's use of a high-priority distress call for a seemingly trivial matter, and complies minimally.

Interstellar trader Cyrano Jones arrives with goods for sale, among them purring balls of fluff called tribbles.

Doctor Leonard McCoy and Spock are concerned that the increasing number of tribbles threatens to consume all the food aboard the Enterprise.

Their arguments are cut short, however, when Baris's assistant Arne Darvin walks into the room and the tribbles react as if in the presence of a Klingon.

Jones is ordered to remove the tribbles from the station (a task that Spock estimates will take 17.9 years), or he may face charges for transporting dangerous life-forms.

Because his typewriter used a less common, smaller size font, an approved screenplay version needed to be reduced by twenty pages before filming.

[5] When Star Trek was first broadcast, he was concerned that it might turn into something similar to Lost in Space, which he has described as "one full-color hour of trash reaching into millions of homes".

[10] He had his best hopes on two treatments called "Bandi" and "The Protracted Man",[11] but decided to submit his fifth story despite Coon's earlier dismissal of the idea.

However, Gerrold's agent was concerned that requiring a miniature of the station to be built as well as the additional sets would cause it to be too expensive for a single episode.

[22] During a visit to the set, Gerrold had the opportunity to speak to Leonard Nimoy and ask his advice on how to write for Spock and was allowed to watch the dailies from each day's shoot of the episode "The Doomsday Machine" which was being filmed at the time.

[27] Both Coon and associate producer Robert Justman gave feedback on the script, and pointed out a few gaps such as there needing to be some way in the plot for the crew to discover that Darvin was a Klingon agent.

In his authorized biography Heinlein said he was called by Gene Coon who gave him a "sob story" about the issue and asked him to waive claim to the "similarity" to his flat cats.

He had misgivings upon seeing the actual script but let it go, an action he later regretted: "If that matter had simply been dropped after that one episode was filmed, I would have chalked it up wryly to experience.

According to Gerrold's account, as their similarity to Heinlein's flat cats was not yet discovered, the inspiration for the form of the tribble instead came from a fluffy keyring owned by Holly Sherman.

[13][44] Six ambulatory tribbles were made using the mechanisms of walking toy dogs, which were quite noisy and required the dialogue to be looped in during editing.

[55] Pevney was one of the two most prolific Original Series directors alongside Marc Daniels, and directed fourteen episodes of the show.

At various points Star Trek creator Gene Roddenberry claimed it was his intention to bring back Koloth during the third season of The Original Series, as Kirk's recurring Klingon adversary.

[62] He did not remember the character's name, only learning it when he first attended a Star Trek convention at a hotel near Los Angeles Airport, as the fans called it out when he entered the lobby.

[67] This effect was later explained in 2012 when Jordon Hoffman on StarTrek.com described "The Trouble with Tribbles" as "quite possibly, the first episode of Star Trek you ever saw".

[74] In a list of the top 100 episodes of the Star Trek franchise, "The Trouble with Tribbles" was placed sixth by Charlie Jane Anders at io9.

[82] They remark "the image of Kirk mired in a pile of adorable fur balls has solidified "The Trouble of Tribbles" in the pop culture lexicon.

[87] 2016 was the 50th anniversary of the first broadcast of Star Trek, which triggered a large amount of press including TV Guide's review of top Original Series episodes.

[96] In 2016, Radio Times also ranked this episode as having the 13th best moment in all Star Trek, pointing out several scenes, but especially the one where Kirk is buried under a mound of tribbles.

[73] In 2009, it was included in a best of collection with three other episodes of The Original Series alongside "Amok Time", "The City on the Edge of Forever" and "Balance of Terror".

[115] "The Trouble with Tribbles" was originally intended to have a follow-up episode during season three, but after Gene Roddenberry stepped back from the production of the show after a time-slot change and further cuts in the budget, the idea was scrapped.

[123] It appears in the scene where Kirk (Chris Pine) and Spock Prime (Leonard Nimoy) meet Scott (Simon Pegg) on the Vulcan moon.

[123] Both his Original Series pitch "The Protracted Man" and his Star Trek: The Next Generation script Blood and Fire have been turned into episodes of New Voyages.