Background: In addition to being the most accessible medical center in the community, the pharmacy is a center for storing and providing medicines and cosmetics that are directly related to people's health. Therefore, observing environmental health issues in the pharmacy, which is managed by the pharmacist, is considered necessary. In this study, considering the direct and high impact of observing various aspects of environmental health on the good pharmacy practice and its value, it has been tried by examining the level of knowledge, attitude and practice of pharmacists in the pharmacies of Tehran city and presenting it, the necessary ground for promotion The environmental health status of pharmacies should be provided. Methods: In this research, standard researcher-made questionnaires were designed and after checking its validity by clinical pharmacists, environmental health and biostatistics experts and its reliability with Cronbach's alpha test, It was completed by the pharmacists of Tehran community pharmacies in the period of April to September 2022, observing ethical points and preserving their identity, in order to show their knowledge, attitude and performance towards environmental health issues in the pharmacy where they operate. Then the obtained data were analyzed in SPSS version 23.0 statistical software. Results: Examination of the data obtained from this study showed that the pharmacists in the study have the appropriate level of knowledge and attitude, but their performance in pharmacies is different. Conclusion: Observation of the results of the study shows that due to the lack of appropriate practical training and the lack of strict rules by regulatory authorities, despite the appropriate level of knowledge of pharmacists, in practice do not consider themselves very obliged to observe health principles.