The increasing number of the patients requiring admission to the intensive care unit and growing demand for the outcome analysis was noted over the last decade. The goal of this study was to evaluate the characteristics of the patients, to compare the outcome of surgical and medical patients, and to demonstrate the importance of the clinical information system in the intensive care. During 12-month period 1031 patients were enrolled for the study. Data were collected on forms and then entered into a computer program specifically designed for this study. For the overall population mean age was 63 years, Simplified Acute Physiology Score II (SAPS II)--31, and stay in the intensive care unit--4 days. The most frequent site of the intensive care unit acquired infection was respiratory, mainly pneumonia. The overall mortality in the intensive care unit was 19.4% and hospital mortality--24.8%. The mortality was directly associated with advanced age, increased SAPS II sore, and the occurrence of organ dysfunction. Medical patients in comparison with surgical patients had higher SAPS II scores (p < 0.001) and number of organ dysfunctions (p < 0.001), longer intensive care unit stay (p < 0.001) and higher mortality rate (p < 0.001). The underprediction of actual mortality by the SAPS II system was predetermined by this value of the neurological patients. The outcome of the surgical patients was good compared to the results of the studies from other countries. Clinical information system is necessary for comprehensive and objective evaluation of the intensive care unit data and quality of therapy.