Two hemophiliac patients with nephrolithiasis were treated with extracorporeal lithotripsy. Both patients were followed up by the 2nd Hemophilia Center of Athens. One is registered as severe hemophilia A and the other one suffers from hemophilia B. With the cooperation of the specialized center they were prepared as for a major operation by administration of substitution therapy. The least possible number of shock waves at low voltage was administered in order to minimize renal damage. Both patients had an uneventful postoperative course.