Louis has enjoyed success in USA television shows, such as a prominent guest appearance on Relic Hunter with Tia Carrere. Louis is probably most famous for his role in the movie My Big Fat Greek Wedding. Other major roles include playing Louis Malone in Martial Law alongside Sammo Hung. However, the show only lasted two series, with Mandylor being dropped at the end of its first run.

Mandylor appeared in the sitcom Friends, pretending to be Joey's twin in The One With Unagi. He also appeared alongside his brother in the Charmed episode Saving Private Leo

He also appeared in the third season of CSI: Miami as a robber/killer