Patient education is generally regarded as an essential component of the clinical management of diabetes. However, analysis of the role of patient education in diabetes control has been limited. Formal patient teaching programs at several medical centers range in operation from merely providing knowledge about diabetes to integrating patient education into the chronic health care system. Improvements in knowledge about diabetes have been demonstrated with patients who have been given questionnaires before and after instruction, but changes in diabetes control and other clinical parameters have not necessarily followed. In those cases in which patient education has been a part of a comprehensive improvement in the entire clinical management of diabetes, significant decreases in rates of hospitalization and acute complications have occurred. Guidelines for future evaluations are discussed.