Background and Introduction: In Brazil, the Telemedicine University Network (RUTE) initiative promotes collaboration between university hospitals, teaching hospitals, health professionals, and students using information and communication technology infrastructure to support special interest groups (SIGs) in health care. Health professionals in institutions belonging to RUTE plan a program of video conferences and/or web conferences to discuss specific themes. This article presents the results of an analysis of collaboration in these SIGs. Materials and Methods: This study uses descriptive statistical analysis and visualization of data contained in management reports provided by RUTE national coordinators for the period between 2007 and 2016 to evaluate the extent of participation in SIGs between institutions associated with RUTE. In this data visualization, we employ concepts from social network theory. Results: The analysis identified the most influential institutions as measured by social network theory metrics. A small number of institutions were found to have many participating SIGs, but most had only a few participating institutions (more than 130 institutions have only one participating SIG). Over the study period, a significant quantitative growth in collaboration occurred, increasing from 21 institutions and 92 participating SIGs in 2007 to 380 institutions and 1,912 participating SIGs in 2016. Conclusion: The growth in collaboration within the network indicates increasing interest and participation in telehealth initiatives in Brazil.