Regional health quality improvement coalitions have aimed to promote and coordinate improvement across various levels and types of health care organizations in particular geographic areas. However, the general factors involved in coalitions' successes or failures are largely unknown. This report looks in depth at four such coalitions-the Cleveland Health Quality Choice Program (now defunct), Minnesota's Institute for Clinical Systems Improvement, the Rochester Health Commission, and the Pittsburgh Regional Healthcare Initiative-and seeks to find common issues and conditions that influence a coalition's sustainability and its success in improving regional health care.