Complications following castration are a potential problem in equine practice. Intestinal evisceration is a life-threatening condition requiring immediate correction. The following case report describes a rare condition associated with post castration evisceration in a 3-year-old Thoroughbred. Shortly after the eviscerated small intestine was repositioned in the abdomen, the horse showed signs of colic and at the second surgery a 4.5 m jejunal loop was found incarcerated in the femoral canal. After resection and anastomosis, the femoral canal was obliterated using large moistened gauze sponges. The horse made a complete recovery and returned to race training. The occurrence of femoral hernia, a condition fairly common in man, has been described but no clinical cases have been reported in horses. This is a severe, although rare, complication after castration.