A report is presented on 25 fatigue fractures of the femoral neck in 20-year-old military recruits with an otherwise healthy skeleton. The problems of diagnosis are described. Principles for the treatment of these stress fractures are elaborated on the basis of pathophysiological considerations and of the clinical experience. A fracture in the radiological stage I (Endosteal callus formation) should be treated conservatively with immobilisation. In stage II (fissure at the calcar), and indication for surgery is relative, whereas in stage III (complete fracture of the femoral neck), a screw osteosynthesis should be carried out. Whereas the fatigue fractures in stages I and II usually heal without postoperative effects, complications are common in stage III, as in all femoral neck fractures.