We prospectively studied 367 patients who had a fracture of the hip, to determine the effect of an operative delay on postoperative complications and on the one-year mortality rate. All of the patients were at least sixty-five years old, cognitively intact, living at home, and able to walk before the fracture. An operative delay was defined as an interval of three calendar days or more between the time of admission to the hospital and the operation. The operation was performed within two calendar days after admission in 267 (73 per cent) of the patients. When the factors of the patient's age and sex and the number of pre-existing medical conditions were controlled, it was found that an operative delay beyond this period approximately doubled the risk of the patient dying before the end of the first postoperative year. When the patient's age and sex and the severity of pre-existing medical conditions were controlled, there was also an increase in mortality associated with an operative delay, although this was not significant. With the numbers studied, an operative delay beyond two calendar days did not have a significant effect on the prevalence of complications during hospitalization. We concluded that an operative delay of more than two calendar days after admission is an important predictor of mortality within one year for elderly patients who have a fracture of the hip and who are cognitively intact, able to walk, and living at home before the fracture. Optimally, such patients should have the operation within two calendar days after admission to the hospital.