The results of the treatment of 166 patients with intracapsular fractures of the femoral neck during a 30-month period are reviewed. A protocol was adopted whereby patients younger than 65 years of age, together with those with undisplaced fractures, were treated with internal fixation, whereas patients older than 85 years of age were treated with primary hemiarthroplasty. The remaining 120 patients, aged 65-85 years, with displaced fractures were carefully evaluated preoperatively using a scoring system of their physiologic status. The more ambulant and independent patients who were medically fit and mentally alert, with good proximal femoral bone stock, who achieved a physiologic status score (PSS) of 20 or more from a maximum of 26, were managed by reduction and internal fixation of their fractures. Those patients with a PSS below 20 were treated with replacement arthroplasty. At a mean of 21 months postfracture, the mortality was 14%, although, among survivors, there was a low incidence of fracture-related complications, with only 5% of the total group requiring reoperation for infection, internal fixation failure, or prosthetic dislocation. The functional outcome was satisfactory in both treatment groups, although the mean scores for regained mobility and final placement more closely approximated the prefracture scores in the patients undergoing internal fixation. The authors conclude that preoperative assessment of the PSS is a useful guide in determining the appropriate treatment for these fractures, and that internal fixation in the 42% of patients aged 65-85 years with a high PSS appears to be well justified.