The incidence and nature of headache before and after operation were investigated in eighty-three of a consecutive series of gynaecological patients. There was a significantly higher incidence of pre-operative and postoperative headache in unpremedicated minor cases than in premedicated minor and major cases. It was found that the incidence of both pre-operative and postoperative headache was higher in those cases who had given a history of migraine. Factors which may have played a part in the development of headaches in these patients are discussed.