- as Harold Lee
- as Billy Carver
- as J.D.
- as Dr. Willoughby
- as Kumar Patel
- as Cole
- as Maria
- as Goldstein
- as Rosenberg
- as Mean Tollbooth Guy
- as Burger Shack Employee
- as Kenneth Park
- as Hippie Student
- as Christy
- as Clarissa
- as Dr. Patel
- as Saikat Patel
- as Male Nurse
- as E.R. Patient
- as Freakshow
- as Liane
- as Neil Patrick Harris
- as Officer Palumbo
- as Tarik
- as Officer Martone
- as Giant Bag of Weed
- as Officer Brucks
- as White Castle Teenager
- as Hayden (Cameo)
- as Tony (Cameo)
Watch "Harold and Kumar Go to White Castle":