Somatization disorder is a chronic psychological condition that causes numerous physical complaints for which no underlying physical problem can be identified. The disorder often lasts for several years and results in substantial functional impairment. The physical complaints most frequently involve chronic pain and problems with the digestive, nervous, and reproductive systems. Neither pharmacological nor psychosocial treatments for this disorder have been successful in suppressing symptoms. Cognitive behavioral therapy (CBT) is a treatment that focuses on maladaptive patterns of thinking and the beliefs that underlie such thinking. This study will examine the long-term effects of CBT on the physical symptoms, functioning, and health care utilization of people with somatization disorder.