Giant cell tumor (GCT) is one of the most common tumors of bone and is the most common precursor of aneurysmal bone cysts (ABC). The clinical behavior of concurrent GCT and ABC can be very aggressive in children. GCT of the ribs, with or without ABC, is rarely seen in children. We report a case of an 8-year-old girl with GCT and associated ABC of the ribs who presented with sudden onset of chest pain and breathlessness due to a hemothorax. The patient was successfully treated by surgical resections and arterial embolization. She has remained well for 4 years after the initial surgery.