PURPOSE OF THE STUDY We aimed to determine the incidence of pressure sores and their effect on survival in patients older than 70 years who underwent surgery for hip fracture, and to identify the factors which were associated with an increased risk of pressure sores. MATERIAL AND METHODS The group comprised 269 patients (219 women and 50 men) older than 70 years who underwent surgery for proximal femoral fractures in the Trauma center between January 2003 and June 2005. Follow-up ranged from 12 to 18 months. In a prospective study we assessed relevant medical history, demographic and clinical data, pre-, intra-, and post-ope- rative factors and the presence, location and depth of pressure sores. Statistical significance at a 5 % level of probability was determined by testing null hypotheses for qualitative and quan- titative variables, using multivariate analysis adjusted for selected baseline characteristics. RESULTS The average age of the patient group was 81 years (range, 70-99). Pressure ulcers developed in 92 patients (34.2 %); their presence in the post-operative period significantly reduced patient survival (p=0.037). In terms of location, pressure ulcers in the calcaneal region had a more significant effect on patient mortality (p=0.011) than those in the sacral region (p=0.130). Age was not significantly associated with pressure ulcer development (p=0.547), in contrast to male gender (p=0.007). A lower mobility score before injury was a significant risk factor (p=0.007). Co-morbidities adjusted for age and gender had a significant effect (p=0.003). The factors that did not significantly increase the risk of pressure ulcers were as follows: the patient's living environment before injury (p=0.113), AO type of fracture (p=0.653), type of anaesthesia (p=0.702), surgical procedure used (p=0.946), morbidity before injury (p=0.267) and time to surgery (p=0.180). The presence of acu- te complications was of boundary significance (p=0.083). DISCUSSION The study included only the patients with proximal femoral fractures who underwent surgery. It was the authors' view that, by excluding conservatively treated patients, a more homogenous group was achieved. There is only sparse information in the literature concerning the effect of pressure ulcers on reduced patient survival, and the significance of pressure ulcer location has not been evaluated at all. Similarly, the effect of pre-morbidity on pres- sure ulcer development has not been reported in any of the studies available. In contrast to other studies, the authors did not find age to be a risk factor for increased ulcer development. They believe that the quality and quantity of the input data (prospective data collection, large sample size, long follow-up) guarantee the validity of the results obtained in this study. The incidence of pressure sores is in agreement with the results of relevant studies involving large numbers of patients and prolonged follow-up. CONCLUSIONS In patients older than 70 years undergoing surgery for hip fracture, the development of pressure ulcers had a significant effect on reduced survival, with the highest significance for ulcers in the calcaneal region. Factors significantly increasing the risk of ulcer development were male gender, morbidity before injury and pre-existing chronic complications. The pre- sence of acute complications was of boundary significance. The study did not show any significant effect of age, pre-mor- bidities, time to surgery, patient's living environment before injury, fracture type, type of anaesthesia or surgical procedure used on the incidence of pressure ulcers. Key words: hip fracture, pressure ulcers, mortality, risk factors.