One hundred and fifty-six women with menorrhagia of benign origin were interviewed before hysterectomy, and re-interviewed six months post-operatively (n = 147), and again 18 months post-operatively (n = 148). Levels of psychiatric morbidity were significantly higher before the operation than after. On the Present State Examination, 58 per cent of patients were psychiatric cases before surgery, as against 29 per cent at the 18-month follow-up. Similar post-operative improvements were found on measures of mood (POMS), and of psychosexual and social functioning. Most of these improvements had occurred within three to six months after the operation. Both before and after hysterectomy, levels of psychiatric morbidity were high by comparison with women in the general population, but lower than in psychiatric patients. The pre-operative psychiatric morbidity had been mainly of long duration.