BACKGROUND: The aim of the current prospective study was to examine the prognostic value of APACHE II, APACHE III (Acute Physiology and Chronic Health Evakuation II and III) and SOFA (Sepsis-related Organ Failure Assessment) scores and platelet counts in septic and nonseptic patients hospitalized and treated in ICU units. METHODS: One hundred and twenty ICU patients were included in this study. Patients were grouped as septic survivors, septic nonsurvivors, nonseptic survivors and nonseptic nonsurvivors. The SOFA, APACHE II and III scores, and platelet counts were recorded at the admission in the ICU units and discharge.from the hospital. RESULTS: Patients were grouped as septic survivors (n=42), septic nonsurvivors (n=14), nonseptic survivors (n=48) and nonseptic nonsurvivors (n=16). The highest SOFA, APACHE II and III scores and the lowest platelet counts were observed in septic nonsurvivors when compared with the other patient groups.. All score values and platelet counts were found to be significant in prediction of mortality in septic patients. CONCLUSIONS: According to our results obtained in septic and non-septic patients, we concluded that SOFA, APACHE II and III scores and platelet counts might be used in the prediction of mortality in septic patients.