Different structures exist in which primary care physicians and mental health professionals may work together. Five such models are reviewed, with an emphasis on four different options for the private practice setting. Collaborative practices are presented as developmental processes that evolve differently according to specific situations and the needs of physicians, therapists, and patients. Three case studies are provided that demonstrate developmental processes as they occurred in three different practice settings. These settings include a small, single physician private practice; a growing multi-physician/multitherapist private practice; and an academic medicine setting. The case studies demonstrate benefits of collaborative practices for practitioners and patients. Physicians and therapists are encouraged to pursue creatively the development of collaborative practices in their own unique settings. The training of primary care physicians in collaborative models is discussed.