OBJECTIVE: In hospital and health care organizational factors may be changed to reduce postoperative mortality. The aim of this study is to evaluate a possible association between mortality and 'length of hospital stay', 'priority of surgery', 'time of surgery', or 'surgical delay' in hip fracture surgery. DESIGN: Observational cohort study. SETTING: Prospectively and consecutively reported data from the Danish Anaesthesia Database were linked to The Danish National Registry of Patients and The Civil Registration System. Records on vital status, admittance, discharges, codes of diagnosis, anaesthetic and surgical procedures were retrieved. PARTICIPANTS: 6143 patients aged more than 65 years undergoing hip fracture surgery. MAIN OUTCOME MEASURES: All-cause mortality. RESULTS: The one year mortality was 30% (28-31%, 95% Confidence interval (CI)). In a multivariate model 'length of hospital stay' less than 10 days and more than 20 days are associated with mortality with hazard ratios of 1.34 (1.20-1.53 CI, p<0.001) and 1.27 (1.06-1.51 CI, p<0.001), respectively. 'Priority of surgery' categorized as 'non-scheduled' is associated with mortality with a hazard ratio of 1.31 (1.13-1.50 CI, p<0.001). Surgical delay and time of surgery are not significantly associated with mortality. CONCLUSION: Non-scheduled surgery and length of hospital stay were associated with increased mortality. Confounding by indication may bias observational studies evaluating early and late discharge as well as priority; therefore cluster randomized clinical trials comparing different clinical set ups may be warranted evaluating health care organizational factors.