Reyes, Jr. played a prince in the 1985 production, Red Sonja. In that movie, he shared the screen with Arnold Schwarzenegger and Brigitte Nielsen. He also appeared in an episode of the hit television series MacGyver in 1988. Reyes had starring roles in Surf Ninjas and in the second Teenage Mutant Ninja Turtles film The Secret of the Ooze as Keno, the pizza delivery boy. He also served as the martial arts stunt double for Donatello in the first Ninja Turtles film. He later appeared in movies such as Rush Hour 2 playing Zing and in The Rundown alongside WWE wrestler Dwayne “The Rock” Johnson. Reyes guest starred in the TV series Kung Fu: The Legend Continues alongside David Carradine.
Ernie Reyes Jr. has a professional fight record of 3–0 in Strikeforce which is now one of largest Mixed martial arts organization on the planet but started out as a Muay Thai and kickboxing organization.
More recently Ernie Reyes Jr. has done motion capture stunts for blockbuster movies such as Avatar and Alice in Wonderland. Currently he stars in the mixed martial arts movie The Red Canvas co-starring Ving Rhames and UFC lightweight number one contender Gray Maynard.