Audit firm faces complex issues such as conflict of interest, fierce competition, lack of intellectual capital, underdevelopment, and stakeholders' expectations gap. On the other hand, social capital is recognized as a fundamental solution to reconciling conflicts and strengthening trust, cooperation, synergy, and development. In this regard, the purpose of the present study is to explain the framework of social capital in the context of Iranian auditing firms. For this aim, the qualitative grounded theory method and a triangulation data collection including 25 semi-structured interviews, 38 secondary interviews, and the qualitative analysis of 548 documents from professional magazines of the country have been used in the present study. The results showed that the social capital of Iranian auditing firms can be explained from two perspectives, within the organization and outside the organization, and three structural, cognitive, and relational dimensions. In short, the structural dimension includes the organization, roles, and internal and external relations of the organization, the cognitive dimension includes the norms and policies of the organization's internal and external interactions, and the relationship dimension includes trust, intellectual capital, synergy, and legitimacy that is gained by the firm through the other two dimensions of income. Each dimension of the research framework explains several categories and contextual concepts that overall provide a comprehensive and coherent theoretical framework for the promotion and development of the country's auditing firms.