This article focuses on quantitative and qualitative changes in rat testes after methadone and buprenorphine administration. Considering high prevalence of Opiate abuse and treatment of Opiate addiction among adolescent men, it is necessary to find out the effects of these drugs on testes. This study is recommended to Basic medical sciences researchers, Urologists, Psychologists, and also for informing the general population, particularly the youth, of the probable consequences of opioids drugs.