Numerous methodological issues arise when studying teams that span multiple boundaries. The main purpose of this paper is to raise awareness about the challenges of conducting field research on teams in global firms. Based on field research across multiple firms (software development, product development, financial services, and high technology), we outline five types of boundaries that we encountered in our field research (geographical, functional, temporal, identity, and organizational) and discuss methodological issues in distinguishing the effects of one boundary where multiple boundaries exist. We suggest that it is important to: (1) appropriately measure the boundary of interest to the study, (2) assess and control for other influential boundaries within and across teams, and (3) distinguish the effects of each boundary on each team outcome of interest. Only through careful attention to methodology can we properly assess the effects of team boundaries and appreciate their research and practical implications for designing and using information systems to support collaborative work.