AIM. The aim of this study was to evaluate the relationship between clinical characteristics and the frequency of pressure ulcers in ICU patients. MATERIAL-METHOD. The study was performed in ICU, University Hospital of Larissa. All patients who have been nursed in the ICU between 1/1/2006 – 31/12/2006 were included in the study (n=210). Cubbin and Jackson Scale was used to identify high risk patients for pressure ulcers. RESULTS. The Prevalence of pressure ulcers in ICU patients was 24,3%. Multiple logistic regression showed that age (OR=1,04 P=0,027), duration of nursing (OR=1,17 P=0,000), haemodialysis (OR=4,09 P=0,033) and haematocrit (OR=0,91 P=0,045) were depend risk factors for the presence of pressure ulcers. CONCLUSIONS. The risk factors (determinants) of pressure ulcers were found, were similar than previously reported historical data. However, new therapeutic and preventive strategies and advances in nursing care are warranted to improve further the management for pressure ulcers.