This review of health care team effectiveness literature from 1985 to 2004 distinguishes among intervention studies that compare team with usual (nonteam) care; intervention studies that examine the impact of team redesign on team effectiveness; and field studies that explore relationships between team context, structure, processes, and outcomes. The authors use an Integrated Team Effectiveness Model (ITEM) to summarize research findings and to identify gaps in the literature. Their analysis suggests that the type and diversity of clinical expertise involved in team decision making largely accounts for improvements in patient care and organizational effectiveness. Collaboration, conflict resolution, participation, and cohesion are most likely to influence staff satisfaction and perceived team effectiveness. The studies examined here underscore the importance of considering the contexts in which teams are embedded. The ITEM provides a useful framework for conceptualizing relationships between multiple dimensions of team context, structure, processes, and outcomes.