The purpose of this study was to investigate ways of reducing and controlling blood loss and postoperative anaemia in total condylar knee arthroplasty performed under tourniquet. The study covers a two year period to December 1982. Reduction of blood loss was successfully achieved by being aware of the very rich blood supply to the knee and utilizing diathermy for potential bleeders before and after the release of the tourniquet and employing various haemostatic measures. All these patients need blood transfusion, as well as the measures to reduce blood loss, so that they do not become anaemic postoperatively.