Dysmorphophobia (body dysmorphic disorder), defined as a preoccupation with an imaginary or minimal defect in appearance, has been known for more than a century but has received relatively little empirical study. The authors investigated the demographics, phenomenology, course, associated psychopathology and family history in a series of 58 patients (34 men and 24 women) with the disorder. The patients were assessed with the Hopkins Symptom Checklist and two specially constructed instruments developed by the authors. The mean age at onset of body dysmorphic disorder was 17 (sd = 3.8) years and the average duration was 9 (sd = 5.3) years. The most common preoccupations were defects of the face, nose, genitals and legs. Seventy-nine percent of the patients reported excessive mirror checking and 53% reported attempts to camouflage their 'deformities'. As a result of their symptoms, 89.6% avoided the usual social activities, 51.7% showed an impairment of their academic or job performance, 45% experienced suicidal ideation and 36% showed aggressive behaviour. Seventy-two percent of the patients had an associated lifetime diagnosis of a major mood disorder and 74% of an anxiety disorder. Body dysmorphic disorder has a generally chronic course, causes considerable distress and a serious impairment in many areas, and shows strong links with mood and obsessive-compulsive disorders.