Objective: The present study aimed to determine the profit/loss ratio and the service costs in intensive care unit (ICU) based on the length ofICU stay.Methods: This retrospective study reviewed the medical records of 458 patients who were admitted to ICU between August 2016 and August2017. Depending on the length of their ICU stay, the patients were divided into six groups: (I) 1 day, (II) 2 days, (III) 3 days, (IV) 4 days, (V) 5days and (VI) more than 5 days. These charges were evaluated under six categories: surgery, laboratory tests, drugs, tools and equipment, radiographic workup and others.Results: This study reviewed the medical records of patients including 273 (59.6%) men and 185 (40.4%) women. The mean age of the patientswas 53.87±22.6 years. The profit/loss ratio was in favour of loss in group I (12,870.82 TL), group II (9,384.61 TL) and group III (371.18 TL).The ration was in favour of profit in group IV (16,505.4 TL). Total service costs comprised 38.51% drug costs, 24.45% tools/equipment, 13.14%laboratory tests, 10% other costs, 4.92% surgical costs and 3.1% radiographic tests.Conclusion: The cost analysis based on the service costs in ICU with regards to the length of ICU stay revealed that due to the greater useof diagnostic, surgical and medical tools and equipment and laboratory and radiographic tests, the profit/loss ratio was in favour of loss withinthe first three days in ICU. This ratio turned to profit beginning from day 4 in ICU due to the decrease in the use of these equipment and tests.Moreover, total ICU costs comprised 38.51% drug costs and 24.45% medical tools and equipment.