Aunt Vivian (Jamie Lee Curtis) leaves her beloved chihuahua Chloe (Drew Barrymore) in the care of her careless niece Rachel (Piper Perabo). Chloe is accustomed to a typical Beverly Hills life of expensive food, trainers, groomers, a would-be suitor named Papi, and the glitz of belonging to one of the very rich and famous. Rachel leaves with friend to journey to Mexico to enjoy the wildlife, neglecting Chloe's busy schedule of playdates and grooming. Chloe resents her sudden demotion in attention and runs away, eventually being captured by dog fighters. She befriends a German Shepherd, Delgado (Andy Garcia), who rescues her and helps her to be reunited with Rachel.