Objective: Dental wastes are one of the environmental issues which are of great importance due to having hazardous, toxic, and pathogenic agents such as infectious, medical, chemical, and toxic wastes. The objective of this study was to determine the quality, quantity, and management of dental wastes in 4 dental clinics in Tehran. Methods: In this cross-sectional descriptive study, the study area was consisted of 4 dental clinics in west, center, east, and north of Tehran city. Overall, 195 samples were taken. Then, the wastes were manually segmented and divided into 36 parts. In continue they were weighted using a laboratory scale. In order to examine the current state and the implementation process of hazardous dental waste management, we applied a checklist technique which was containing 54 questions. Results: According to the obtained scores, management quality of 3 clinics was proved to be at an average level and only clinic number 4 was perfectly managed. The capita percentage for infectious waste except for clinic 1, which was 50%, was 48% for all clinics. The capita percentage for chemical-pharmaceutical waste except for clinic 1, which was 36%, was 48% for all clinics. The amount of toxic waste for each clinic was 13%. The averages of infectious, toxic and chemical-pharmaceutical wastes were 187.09 ± 9.81, 48.38 ± 1.4, and 147± 4.33 g per capita per day, respectively. Conclusion: Considering the existence of different types of materials with different components and various features in dental wastes, their optimal management must be done based on their specific features which are include plans for generation reduction, segmentation, separation, and recycling of these wastes.