Sciatic nerve palsy is a well-recognised complication of total hip arthroplasty, and causes include direct injury during surgery (crushing or electrocautery), compression or stretching of the nerve, thermal damage caused by leaked bone cement, trauma during dislocation or reduction of the hip, haematoma, traction caused by leg lengthening or inadvertent intraneural injection from nerve blocks. We describe what we believe to be a case of sciatic nerve ischemia due to intra-operative arterial occlusion, and we discuss the vascular anatomy which may have contributed.