Despite the recent dramatic increase in the use of video for patient education, there has been no critical assessment of this medium. In this paper, the author reviews 25 methodologically-sound studies in order to define the efficacy and limitations of video. Video is as good as and often more effective than traditional methods of patient education in increasing short-term knowledge. It offers no advantage, however, in improving long-term retention of knowledge or in promoting compliance with medical regimens. A strength of video is role-modeling. When applied to well-defined, self-limited stressful situations, role-modeling in video decreases patients' anxiety, pain, and sympathetic arousal while increasing knowledge, cooperation, and coping ability. These effects may carry over for patients to less structured but similarly stressful situations.