In 2007, Cho was added to the cast of Ugly Betty as a recurring character. Of the latter, Staci Krause of IGN, wrote that Cho was "the scene stealer in this episode" and that she would "definitely like to see more of him" in the series.
Cho has indicated he has found freedom in being Harold in the Harold and Kumar films because the stoner character goes against the grain of Asian Americans onscreen. is bit of a landmark,” he has said on the inability of Asians getting offered such roles.
When asked to do an Asian accent for Big Fat Liar, Cho refused.
Early in his career, Cho also starred in the Asian American centered films Better Luck Tomorrow (2002), Shopping for Fangs (1997), and Yellow (1998).
On television, Cho played FBI agent Demetri Noh in the science fiction television drama Flash Forward; Chau Presley on the sitcom Off Centre; Andy Brooks in the horror drama Sleepy Hollow, Henry Higgs in the 2014 sitcom Selfie, and Andrew Kim in The Exorcist.
In 2002, he had a starring role in the ensemble cast of Justin Lin's Better Luck Tomorrow, a drama focusing on the travails of a group of Asian Americans living in Southern California who are academically successful but socially discontented, and as a result engage in wantonly violent, criminal behavior.