Background: Medical wastes are one of the health and environmental challenges across the globe. Also, hospitals are one of the most important medical waste generators. Methods: In this study, the quantity and composition of solid wastes generated in 10 public hospitals in the city of Tehran were investigated. Medical wastes were classified into four groups and the one-year average was considered. Results: The results showed that the range of waste generation in public hospitals was from 107.5 to 2508 kg/day. Considering account hospital beds, the production of medical wastes in public hospitals was 3.53 kg/bed/day. Moreover, 67.45% of medical wastes in the hospitals studied included common wastes, but infectious and sharp wastes accounted for 31.65% of the medical wastes. Besides, chemical and pharmacy wastes accounted for an average of 0.8% of the medical wastes. Conclusion: Due to the importance of medical waste management, it is necessary to pay more attention to segregation and reduce the proportion of infectious wastes in the hospital studied.