This chapter provides an overview of the importance of patient education in the clinical area of those with diabetes. A historical review of its development is provided, followed by the determinants of success or failure of educational processes. These include the weak relationship between knowledge and behavior, the context of the learning process, patients' perception of their disease and its treatment, non‐acceptance of disease, the need for patient empowerment, perceived benefits and barriers, patient satisfaction and quality of life. Behavioral models of education are reviewed. Recommendations are provided for those planning programs about the choice between different types of program, problems of development of clear‐cut definition of objectives in behavioral terms, choice of learning methods, the use of audiovisual aids and computer based learning materials. Certain specific problems are dealt with in more detail, for example; the initiation of insulin therapy and learning about hypoglycemia. Methods of evaluation of process and outcome are described and the need for these to be repeated on a regular basis stressed. The lifelong process of education and the recognition that all carers are involved and require training in this process, are emphasized.