Background Universities are the first line of social capital production centers in every society, among which the medical universities are the most important because of their great duties to promote common health services and educate professional students. Despite this, there is no standard social capital assessment tool in medical science university in Persian. Therefore, the present study was designed to develop a tool for measuring social capital in Mashhad University of Medical Sciences, in order to improve the level of social capital of faculty members, staff and managers to have a significant impact on the development of this index in the field of health education and student performance. Methods Integrating quantitative and qualitative method has been applied in the present study in Mashhad University of medical sciences during 2019-2020. In the quantitative part, different variables affecting on social capital, obtained using related literature reviews and then they were finalized using Delphi method and expert panels' opinions. In the qualitative part, the proper questionnaire prepared and data analysis performed using structural equation method. Finally, descriptive statistics methods were used to characterize the sociological features of the sample and confirmatory factor analysis was used to evaluate the social capital model, using SPSS software version 20 and LISREL version 8.8. Results We found 7 dimensions for social capital questionnaire and 27 components affecting on social capital dimensions. We also found that there are more different factors influencing on social capital such as structural, communicational, cognitive, management, organizational, group and individual. Also, the overall reliability of the Social Capital Questionnaire was calculated to be 0.893 in Cronbach's alpha, which indicates the high reliability of the research instrument, moreover the calculated values of t for each factor load of each indicator with its hidden structure or variable is above 1.96. Therefore, the Validity of the questionnaire questions to measure the concepts can be validated. Conclusion Based on the findings of this study; we observed that effective components to develop the social capital model in Mashhad university of medical sciences include the component of social accountability system in the structural dimension of social capital, trust in the communication dimension of social capital, perception of justice and job satisfaction in the individual dimension of social capital and knowledge sharing in the organizational dimension of social capital. These components should be socially noticed by university faculty members.