We report our past experience on a sample of patients who underwent pelvic surgery to treat infiltrating bladder tumours.We observed the highest incidence of TVP (33.3%, 3 out of 9) in those patients with higher risk due to anaesthesia and type of surgery. One of our patients died of pulmonary embolism.Abdominal pelvic surgery in tumour-bearing patients can be risky due to high incidence of distal and proximal venous thrombosis often resulting in fatal pulmonary embolism (EP). The general risk factors should be evaluated. The diagnosis of venous thrombosis can be difficult to achieve only by clinical examination. Heparin administration as well as surgical techniques and physiotherapy are used as prophylactic measures to reduce the risk of venous thrombosis and to speed up recovery. Nowadays, there is an increasing risk of running into legal problems if appropriate measures to minimise the thromboembolism are not taken.