37 patients were suspected clinically of having a deep venous thrombosis, 10 of which were confirmed radiologically, giving a rate of 4%. Nine patients had a suspected pulmonary embolism, 2 of which were confirmed radiologically and one of whom died of pulmonary embolism, giving an overall rate of fatal pulmonary embolism of 0.4%. All patients with thromboembolic events had lower extremity tumours and all were surgical patients. However, the majority of thromboembolic events (6 of 10 deep venous thromboses and 2 of 3 pulmonary embolisms) occurred prior to surgery.