Nine patients with soft tissue tumours of the lower limb not amenable to treatment other than by isolated limb perfusion or amputation underwent hyperthermic isolated limb perfusion at the level of the superficial femoral vessels, using a combination of recombinant tumour necrosis factor (TNF) alpha and melphalan. In seven patients with superficial tumours, necrosis and sloughing was apparent within 48 h of perfusion. All patients experienced a complete tumour response. There were no systemic side-effects associated with the use of TNF-alpha although local side-effects, particularly oedema, were pronounced. Three patients ultimately required amputation because of the large soft tissue defects that resulted from necrosis of the tumour and overlying skin.