We report a case of an iliac apophyseal fracture in a 15-year-old boy, sustained while swinging a baseball bat. He presented with right hip pain one hour after the injury occurred. Diagnosis was made on the basis of radiographs of the pelvis. Pelvic avulsion fractures are uncommon injuries, seen almost exclusively in adolescent athletes. The iliac crest is an unusual site of injury for this avulsion fracture. Only one other well-described case of an acute, noncontact fracture of the iliac apophysis with a similar mechanism of injury has been reported.