Purpose - Rural municipality, as an organization for sustainable rural development, is supposed to be a public entity for rural administration supervised by villagers through the Islamic Council. Capital inputs are vital for achieving the best performance of rural municipalities in order to realize the development in rural areas. The main purpose of this article was to investigate the effect of social capital on the performance of rural people. Design/methodology/approach - The study area of this research is located in the villages of Sonqor and Kolyai Counties in Kermanshah Province. The statistical population of this study is 180 villages with rural municipalities, and 123 samples were determined by Cochran's formula. 28 items for rural performance of rural municipalities and 30 items for social capital were utilized to design the questionnaire. Cronbach's alpha method was used for the reliability, and experts’ opinions were used for to determine the validity. The correlation for the collected data was analyzed by Pearson Correlation Coefficient. Finding - The findings confirm that there is a significant relationship between the level of social capital and the performance of the rural municipalities. Among the indicator of social capital, social participation has the highest correlation and social trust has the lowest correlation with the performance of rural municipalities. The variables entered in the regression equation were able to explain 32% of the variance of the dependent variable. In addition, among them, the dependent variable is affected by the social participation at the highest and the social trust at the lowest.