Recent studies of small work groups emphasize comprehensive models of team effectiveness. A survey-based operationalization of one such model, Hackman `s Model of Group Effectiveness (Hackman, 1987, 1990), is applied to 15 interdisciplinary treatment teams working in three public psychiatric hospitals. Mental health professionals answered a self-administered questionnaire I developed (N = 98, response rate = 91%). Analysis was conducted at three levels: (a) by all respondents; (b) by team; and (c) by organizational characteristics and professional discipline, and their interaction. Through use of a structural equation model, particular initial and enabling conditions successfully predict teams' meeting standards of the required task teams' cohesion, and members' personal well-being; standards met and cohesion of team also predict overall team effectiveness. These findings emphasize the importance of measuring the various types of organizational and group factors contributing to team effectiveness, as well as the specific aspects of team effectiveness. Implications for team training are discussed.