We sought to examine the growth of an interdisciplinary center using social network analysis techniques. Specific aims were to examine the patterns of growth and interdisciplinary connectedness of the Center and to identify the social network characteristics of its productive members. The setting for this study was The Center for Interdisciplinary Research on Antimicrobial Resistance (CIRAR) at Columbia University. Periodic surveys and social network analysis comprised the study design. The data for this study included a relational survey taken by all members of the Center at three time points over one year. Respondents confirmed whether or not they had "heard of," "met," or "know the work of," or had "worked with" each of the other Center members. Data were analyzed using the social networking software program Organizational Risk Analyzer (ORA). Over time the social network increased in size, density, centralization, and complexity. The density of connections among and between different disciplines in the Center varied from Time 1 to 2 to 3; some increased, some decreased, while others stayed the same. Finally, the total degree centrality and the betweeness centrality of Center members were highly correlated to productivity. The study shows that a number of characteristics of an interdisciplinary research center can be quantified and described using social network techniques. Data from these analyses can be used to evaluate a center's progress, identify important indicators of leadership, identify areas of strength and need for improvement, and inform decisions on strategic direction. (Contains 2 tables and 3 figures.)