Barrese and her mother had their acting debut in the 1989 movie Homer and Eddie. The following year the pair starred as the younger and older versions of a character named Jezebel in 1990's Jezebel's Kiss. In all subsequent roles, Sasha is credited as Sasha Barrese in lieu of her birth name, Alexandra Barrese. Over the course of her education career Sasha attended 15 different schools. As a young girl, she attended Ojai Valley School in Ojai, California, and Le Lycee Francais in Los Angeles, California. She later went to Tabor Academy in Marion, Massachusetts, and graduated high school in 1999. During high school, she modeled for NEXT Agency, Elite, and Guess Jeans. After graduation, she did work both on television and the silver screen. She had co-starring roles in the films The Hangover, The Hangover Part II, and The Hangover Part III. She also appeared in the 2010 horror film Let Me In.