As a large amount of blood loss is sometimes encountered in limb salvage procedures for pelvic tumours, it is essential to identify risk factors predicting the possibility of extensive haemorrhage. We retrospectively reviewed 137 patients who underwent pelvic tumour resections. Patients with an estimated blood loss greater than 3,000 ml were classified as having a large amount of blood loss. Sixty-one (44.53%) patients had blood loss greater than 3,000 ml. Tumours involving the acetabulum or sacrum, tumour volume greater than 400 cm(3), aorta occlusion, resection method, reconstruction and operative time were all associated with a large amount of blood loss. Pelvic tumours involving the acetabulum or sacrum (odds ratio: 4.837), tumour volume greater than 400 cm(3) (odds ratio: 3.005) and planned operation time of more than 200 min (odds ratio: 3.784) independently predicted a large amount of blood loss. Pelvic tumours with these characteristics were likely to have a large amount of blood loss during surgery.