Understanding of interdisciplinary teamwork is evolving. During health care restructuring, leaders across organizations have challenging responsibilities when work groups must integrate changing organizational values with new modes of service delivery. In this environment, a well-functioning interdisciplinary team in which clinicians work as member-leaders has the potential to further organizational change and foster improvements in patient outcomes. In this paper it is argued that the term interdisciplinary team leadership should be embraced cautiously as it may be a revisionist approach to an old problem, namely a means to modify existing theories of leadership that have been vague and continue to be poorly understood despite considerable effort to explicate knowledge over several decades. Preliminary research suggests that interdisciplinary team leadership is a model of shared leadership that requires more development if it is to become the cornerstone of interdisciplinary team practice in a radically reforming health sector. Stewardship is proposed as a potential philosophy for interdisciplinary team leadership, and a new, shared leadership role of practice leader is suggested.