Numerous side effects of synthetic drugs have caused medicinal plants to be regarded in recent decades as a reliable source of new drugs. Regarding the analgesic effects of many plants that are pointed in traditional medicine of Iran, many studies have been performed in this field that have caused need to be reviewed. In this study, different methods of testing pain, analgesic activity and possible compounds of medicinal plants and also the possible mechanisms actions of these plants are presented. The data presented in this review paper provide scientific information that might be used for isolation of potentially active compounds from some of these medicinal plants in future.