Social workers have worked with colleagues from other disciplines since the early days of the profession; yet, they were without clear models to guide this interdisciplinary work. The author uses multidisciplinary theoretical literature and conceptual and research pieces from social work literature to support the development of such a model. First, current trends relevant to interdisciplinary practice are noted to emphasize its importance. The article describes a two-part model. Part one of the model consists of five components that constitute interdisciplinary collaboration between social workers and other professionals: interdependence, newly created professional activities, flexibility, collective ownership of goals, and reflection on process. Part two of the model consists of four influences on collaboration: professional role, structural characteristics, personal characteristics and a history of collaboration. Implications for social work practice are discussed.