This study examines the effectiveness of a HIV/AIDS peer education program, Teens for AIDS Prevention (TAP) in two cultures. A convenience sample of 287 (American and Nepalese) 9th grade students participated in the study. It was found that HIV/AIDS knowledge scores were significantly higher among American adolescents than their Nepalese counterparts only at pre-intervention. American adolescents had significantly higher self-efficacy scores than Nepalese adolescents both at pre-intervention and post-intervention. Adolescent peer education programs could be used to improve adolescent HIV/AIDS knowledge and self-efficacy for limiting sexual risk behavior; however for the educational programs to be effective, it is pertinent that the program is culturally appropriate to the target population.