Preoperative malnutrition increases the morbidity rate and length of hospitalization for various types of surgical patients. However, among patients who undergo elective total hip replacement, it is unclear how preoperative nutritional data can be used to detect a high risk subgroup. The purpose of this study was to identify preoperative nutritional factors that could be used to define a subgroup of patients who have undergone elective total hip replacement who are at high risk for poor post-operative outcome. Preoperative nutritional factors were evaluated in 89 consecutive patients who underwent elective total hip replacement. An inverse relationship was found between serum albumin and length of stay. Patients with an albumin level less than 3.9 were twice as likely to require prolonged hospitalization ( > 15 days) when compared with those in whom the albumin level was 3.9 or greater. Complications were related to the preoperative orthopaedic diagnosis of avascular necrosis of the hip. A subgroup of the patients undergoing elective total hip replacement who are at risk for prolonged recovery can be identified preoperatively by using a serum albumin level of less than 3.9 g/dL. The traditional normal range for albumin may be inappropriate for these patients.