After internal fixation of a femoral neck fracture, 3 months is the critical time for planning rehabilitation of the patient. Most failures in the elderly occur within this time. In a series of 165 patients, we followed 127 women and 38 men with a median age of 81 (63-97) years from an examination at 3 months to reoperation or survival of the hip. 36 patients had radiographic signs of disturbed healing at the 3-month follow-up--change in fracture position by 10 mm, change in screw position by 5%, backing of the screws by 20 mm, or perforation of the femoral head by the screw. These signs had a high association with local complications and need for a later reoperation. High age and male sex increased this association. Signs of impaired healing made nonunion likely, but did not predict late segmental collapse of the femoral head. Patients with signs of disturbed healing and those closest to them should be informed about the value of early check-ups in case of pain and impaired function.