One thousand six hundred and forty-two vessel segments (46% iliac, 54% femoro-distal) in 1141 patients have undergone percutaneous peripheral balloon dilatation at the Northern General Hospital, Sheffield over a 9 year period. Forty-two significant complications were encountered in all; 28 of these were occlusive and half of these were treated by angioplasty itself, either by thrombolysis or catheter suction. There was one case of distal ischaemia attributed to cholesterol embolisation which led to death (Gaines et al., 1988). There were two cases of perforation and haematoma requiring surgery, one retroperitoneal haemorrhage and one false aneurysm. One diabetic patient developed septicaemia following successful PTA for an ischaemic foot and died. One case each of bowel ischaemia, cerebrovascular accident and myocardial infarction occurred within 24 h of the angioplasty procedure, but there was no clear causal relationship. Arterial wall dissection or perforation per se was not considered a complication unless it progressed to haemorrhage or vessel occlusion. There were three cases of femoral nerve damage causing sensory loss in the thigh, two of which were permanent. Four hundred and thirty-five procedures were performed in patients with rest ischaemia. Of these, 2.8% developed complications requiring surgery, but only 0.9% required reconstructive bypass surgery. For intermittent claudication 1207 procedures were performed, 0.7% of these developed complications requiring surgery but only 0.5% required reconstructive surgery. These results justify the use of angioplasty in the treatment of intermittent claudication and in poor risk patients with threatened limb loss.