Methylphenidate is a useful, proven method for the effective treatment of minimal brain dysfunction (MBD). Dosage should be titrated individually for each patient, and it is best to start with small doses given at least 15 to 30 minutes before meals. Toxicity, side effects, and drug abuse are not major problems. Unfortunately it is not yet possible to determine in advance who will and will not benefit from drug therapy; not all patients do. Treatment of MBD requires a multidisciplinary approach, for no one discipline alone can satisfactorily solve the problems involved. We believe, however, that medicine is the primary therapy in most instances.