One fourth of a physician's office time is used on average for giving information, instructing and counselling. Such patient education takes place mostly in a one-to-one situation where the physician helps his patients to understand and accept their illnesses, to recognise and acknowledge risk behaviours, to make informed treatment decisions, to develop treatment plans, and to cope with problems of maintenance and relapse. The physician must be able to communicate with his patient in a way that fosters the patient's learning and change processes, in order to maximise the medical outcomes and hence the efficacy and effectiveness of his work. Unfortunately the immense therapeutic potential of patient education is still underutilised, in spite of the fact that patient education has a clearly proven impact on health outcomes, such as reducing morbidity and mortality, reducing risk behaviors and risk factors, increasing healthy behaviour as well as patient and doctor satisfaction, and avoiding malpractice litigation. This paper reviews the principles of motivation and doctor-patient communication, presents current models of the patient's learning and change process, derives rules for effective educational communication, and methodological advice for the individual patient education session.