The cartoon opens with Mickey riding on a rhea through the desert. He stops a saloon, the Cantina Argentina, and flirts with the barmaid/dancer, Minnie. As they dance, Minnie is grabbed away by Black Pete, a notorious feline outlaw. Pete abducts Minnie, fleeing on his tiny donkey, with Mickey in pursuit on his now-drunk rhea. They come to a steep hill, which Pete descends by stretching the donkey's forelimbs, and Mickey by soaking the rhea in starch. Pete arrives at a hotel and locks the door, but Mickey uses his tail to lasso a post and cranks himself to the top floor, where Pete has chained Minnie to a wall. They fight using a pair of rapiers hanging on a wall, but Pete disarms Mickey. Mickey grabs a chamberpot from beneath the room's bed and tosses it over Pete's head and frees Minnie. Together, they ride off, sharing a kiss.
As of 2024, the silent version of the short has entered the Public Domain in the United States; the sound version, which had its copyright registered in 1929, will enter the public domain in the United States in 2025.
The Gallopin' Gaucho provides examples of:
- Art Evolution: In the middle of the short even! Mickey and Minnie start off with the large eyes they had from Plane Crazy, but after their dance together, they have their iconic Black Bead Eyes look.
- Blowing Smoke Rings: Mickey shows off to Minnie by lighting a cigarette with his foot and blowing a series of smoke rings through a big one.
- Cats Are Mean: This marks Pete's first encounter with Mickey, as well as his first role as an outright villain, where he is a bandit who kidnaps Minnie.
- Chase Scene: As Pete flees on a donkey far too small to support his girth, Mickey pursues Pete on his inebriated rhea.
- Deranged Animation: A signature of the 1920's art style, Rubber-Hose Limbs and all.
- Does This Remind You of Anything?: Mickey's sword goes limp in the middle of the duel.
- Drinking on Duty: When he needs to chase Pete to rescue Minnie, Mickey's not impressed when he sees his rhea's had a few too many.
- Early-Installment Weirdness: From Mickey and Minnie not wearing their iconic gloves and starting out with the large eyes with sclerae they had in Plane Crazy, to Mickey smoking and drinking, this short is full of it.
- Gaucho: Mickey's occupation in this short.
- Handy Feet: Mickey uses his foot to light a cigarette.
- Horse of a Different Color: Mickey rides a rhea, who also has a fondness for alcohol.
- Huge Rider, Tiny Mount: Pete rides a donkey that can barely carry him. Its belly scrapes the ground whenever Pete rides him.
- I Have You Now, My Pretty: Pete's intentions for Minnie are pretty clear.
- Mr. Vice Guy: Mickey smokes a cigarette and blows smoke rings to flirt with Minnie, then downs a mug of beer like it was water.
- Public Domain Animation: The short's silent version became Public Domain in the United States in 2024; the sound version is still copyrighted until the following year.
- Rescue Romance: The cartoon ends with Mickey and Minnie kissing after he saves her.
- Rubber-Hose Limbs: Minnie and Mickey exhibit this while they're dancing, as does the rhea when it's drunk.
- Shout-Out: The short was intended as a parody of Douglas Fairbanks's 1927 The Gaucho.
- Spexico: The short's setting is a peculiar mashup of Argentinian, Spanish and Mexican culture.
- Spiteful Spit: When Mickey challenges him to a fight over Minnie, Pete spits a wad of chewing tobacco in his face.
- Spring Coil: Mickey and Minnie coil their tails into springs to act as shock absorbers while they kiss on the rhea's back.
- Sultry Belly Dancer: Minnie's occupation at the bar, and she dances like only a 1920's toon can.
- Sword Fight: Mickey and Pete duel over Minnie with a pair of rapiers.
- Toilet Humor: Mickey defeats Pete by covering his head with a chamberpot.
- Your Size May Vary: Pete goes from being massive to about thrice Minnie's size in two scenes.
