A double-blind clinical trial was carried out in 85 patients undergoing surgery to the upper shaft of the femur and to the hip-joint. In the control series, 27% developed pressure-sores before discharge from hospital. In the group in which 80 I.U. of corticotrophin (A.C.T.H.) in gelatin solvent was administered, only 12% developed pressure-sores. 19% of the patients with fractures to the upper shaft of the femur developed sores because accurate timing was not always possible. Prevention was complete in the case of total-hip replacement which is an elective procedure where A.C.T.H. can be administered at the right time to prevent disruptive damage to the microcirculation. It is suggested that the administration of A.C.T.H. should form part of the management of all high-risk surgical situations.