A 12-year-old male presented with an acutely ischaemic leg following a laparotomy for a pelvic abscess secondary to acute appendicitis. A femoral angiogram revealed an embolus at the popliteal artery. Urgent embolectomy was performed with restoration of normal arterial flow. Subsequent investigation revealed a patent foramen ovale. We believe this case represents a paradoxical embolus from a primary pelvic vein thrombosis dislodged at the time of laparotomy.