Isolated limb perfusion with urokinase was used in combination with balloon catheter embolectomy in three patients with extensive vascular thrombosis in the lower limbs after conventional methods of treatment failed to restore perfusion to the lower limb. The technique and its results are described and discussed. It is suggested that isolated limb perfusion with urokinase is safe and is worthy of further investigation in the treatment of critically ischaemic lower limbs.