Learning in collaboration projects with universities and research centers is a common method in recent decades. Some projects have led to learning for the industry, while others have not. This article addresses the issue of what factors in the Iranian oil, gas, and petrochemical industry affect the learning of companies in collaboration projects with universities and research centers. For this purpose, by studying the research background and conducting a qualitative study, the factors affecting the learning of oil, gas, and petrochemical companies in these projects have been identified and then in the quantitative part, the model obtained from the previous stage has been tested. In the qualitative and quantitative parts of the research, the methods of thematic analysis and Structural Equation Modeling have been used, respectively. The research period covers the years 2014 to 2019. The results of the study confirmed the effect of characteristics of university/ research center, industry, mutual relations, collaboration environment, and university team leader on learning of companies. Also, the sub-factors of university/research center dependence on the public budget, cooperation control mechanisms by university, industry, and government, laws, and procedures, the number of interactions, and knowledge management have been identified as the most important effective factors.