Two cats, one crafty but ill-fated, the other a lunkheaded oaf, decide to hunt mice on a Mexican ship and meet Speedy Gonzales, the fastest mouse in all Mexico. Not surprisingly, all their schemes for catching Speedy fail, with violent consequences for the smarter cat.

Speedy comes to the aid of a starving band of Mexican mice who live right across the border from a cheese factory. Sylvester is guarding the border. Speedy gets past Sylvester's defenses to bring back cheese.

Speedy Gonzales helps save two inebriated mice who keep wandering into the sight of a hungry cat.

The majority of male mice in a Mexican village lament the fact that Speedy Gonzales has been getting in between them and the "pretty girls." One of the mice suggests that they get the "gringo pussycat" Sylvester to chase Speedy out of town.