To define groups of patients with inappropriately high health care utilization better, we have studied a group of 41 chronically ill patients to determine their characteristics, symptoms, functional health status, and amount of health care utilization. This group had somatization disorder diagnosed by specific criteria. They can be easily recognized by primary care physicians by their multiple complaints, negative physical examination results, and a history of multiple medical examinations. We found them to be functionally disabled, spending an average of seven days ill in bed each month. They perceived themselves as severely ill and were willing to undergo multiple hospitalizations, diagnostic studies, and operations. Their health care charges were extraordinary, averaging $4,700 annually. The physician can most effectively treat these patients by scheduling regular visits, relying on physical examinations rather than diagnostic studies, and avoiding costly hospitalizations.