Twenty-two studies on the effects of psychological treatment on cancer patients are reviewed. Only studies that compared one or more experimental conditions with at least one control group have been considered. The studies were evaluated with respect to a) research methods, b) psychological interventions, and c) results. Tailored counseling has been shown to be effective with respect to distress, self-concept, (health) locus of control, fatigue, and sexual problems. Structured counseling showed positive effects with respect to depression and distress. Behavioral interventions and hypnosis were effective with respect to specific symptoms such as anxiety, pain, nausea, and vomiting. The research methods, interventions and results of the studies are reviewed critically. Several recommendations for future research are made.