To determine how well anaesthetists in Nigeria determine the need for transfusion based solely on physiological variables and estimated blood loss. To determine the incidence of inappropriate blood transfusion. Anaesthetists in our hospital determine when to transfuse patients based solely on clinical acumen. This may result in inappropriate transfusion especially in this subregion where blood donors are scarce and risk of transmission of infection high. All surgical patients requiring blood transfusion were prospectively studied over 3 months. Transfusion was based solely on the discretion of the attending anaesthetist. Haemoglobin (Hb) concentration was measured prior to transfusion and 24 h postoperatively. Appropriate transfusion was defined as blood transfusion at Hb < 8 g dL(-1) or 10 g dL(-1) in the elderly and those with medical comorbidities. The trigger for transfusion was documented as well as estimated blood loss. Thirty-four patients were studied. The mean pretransfusion Hb was 8.09 +/- 2.45 g dL(-1) (range 4.6-14.2). Twenty-one patients (61.8%) had appropriate blood transfusion. The commonest transfusion triggers were clinical pallor (82.4%), excessive blood loss (76.4%), delayed capillary refill (55.9%) and severe hypotension (50%). The use of near patient monitoring devices might further improve blood transfusion practice in this setting where donor blood is scarce.