Background and purpose: Police officials are more seeking to eliminate crime grounds in the society by using non-criminal methods and by adopting preventive policies and programs. Mosques are one of the important centers of prevention that can play an essential role in Islamic society in this field. This article was compiled with the aim of investigating the cultural and social performance of mosques in preventing youth crimes with three hypotheses. Methodology: A survey method was used to test the hypotheses, and a researcher-made questionnaire was used, and the statistical population of this research is all people who go to mosques. Yazd city and the sample size is 384 people. The research method was cluster sampling (multi-stage) in which two mosques were selected from each affluent, middle-class and deprived area, and finally, 64 people from each mosque completed the questionnaire. The data collection tool was a researcher-made questionnaire, the validity of which was checked by taking the opinion of knowledgeable experts and professors, and the reliability of the research questions was checked through Cronbach's alpha, the total value of which was 0.85. Findings and results: The results of the research showed that cultural and social performance Mosques play a role in the prevention of youth crimes, and in the meantime, planning to fill youth free time and strengthen self-confidence and self-control in youth are more effective than other functions of mosques in preventing youth crimes.