Objective: The current research aims to investigate the co-authorship network of Iranian universities and research institutions in informetrics research during 2002-2012 using social network analysis. Methodology: Using scientometric approach and social network analysis measures, this paper studies co-authorship network of Iranian universities and research institutions in informetrics research. The research population includes 779 articles published in both English and Persian and indexed in 4th edition of scientometrics bibliography during 2002-2012. First, the co-authorship matrix of institutions was drawn by using excel software second, the UCINET and VOSviewer software were utilized for data analysis. Findings: Results revealed that institutions like Tehran University, Tehran University of Medical Sciences, Islamic Azad University, Tarbiat Modares University, Shahed University, Shahid Chamran University of Aheaz, Regional Information Center for Science and Technology, and National Research Institute for Science Policy play the most important and central roles in the informetrics collaboration network based on productivity, centrality, and collaboration measures. The highest number of co-authored papers in this network have been written by the following pairs of institutions: “Tarbiat Modares University- Shahed University”, “Payame Noor University- Regional Information Center for Science and Technology”, and “Shahed University- National Research Institute for Science Policy” respectively. Conclusion: Results of the clique analysis showed that this network is made of 12 cliques with at least 5 institutions. Tehran University and Islamic Azad University were in the highest number of subgroups of the network with 7 cliques.