The aim was to evaluate the nutritional situation of patients admitted to the Postoperative Acute Care Unit using classic methods of objective anthropometry, systemic evaluation methods, and Nutrition Risk in Critically Ill (NUTRIC) score, and to compare them as a predictor of morbidity and mortality.At admission to the postoperative care unit, patients undergoing various surgeries were assessed for the following items: Subjective Global Assessment (SGA), Nutritional Risk Index (NRI), Nutritional Risk Screening (NRS)-2002, Mini Nutritional Assessment (MNA), Charlson comorbidity index (CCI), and NUTRIC score, anthropometric measurements, serum total protein, serum albumin, and lymphocyte count. Patients were monitored for postoperative complications until death or discharge. Correlation of complications with these parameters was also analyzed.A total of 152 patients were included in the study. In this study a positive correlation was determined between mortality and NRS-2002, SGA, CCI, Acute Physiology and Chronic Health Evaluation , Sepsis-related Organ Failure Assessment, and NUTRIC score, whereas a negative correlation was determined between mortality and NRI. There was a correlation between NUTRIC score and pneumonia, development of atrial fibrillation, delirium, renal failure, inotrope use, and duration of mechanical ventilation. In our study group of postoperative patients, MNA had no predictive properties for any complication, whereas SGA had no predictive properties for any complications other than duration of hospital stay and mortality.The NUTRIC score is an important indicator of mortality and morbidity in postoperative surgical patients. NRI correlated with many postoperative complications, and though SGA and NRS were correlated with mortality, they were not correlated with the majority of complications. MNA was determined not to have any correlation with any complication, mortality, and duration of hospital stay in our patient group.