Background Malnutrition in hospitalized patients is a serious problem and is associated with a number of adverse outcomes. The Nutritional Risk Screening-2002 (NRS-2002) tool was designed to identify patients at nutrition risk. The validation of NRS-2002 compared with detailed clinical assessment of nutrition status was not studied before in hospitalized Turkish adults. The aim of this study is to determine validity, sensitivity, and specificity of the Turkish version of NRS-2002 in a hospitalized adult population. Methods A total of 271 consecutive hospitalized patients aged >18 years admitted to surgical and medical wards of a university hospital in Turkey were included in this single-center non interventional validity study. Assessment by geriatricians was used as the reference method. Two geriatricians experienced in the field of malnutrition interpreted the patients' nutrition status after the evaluation of several parameters. Patients were divided into "at nutrition risk" and "not at nutrition risk" groups by geriatricians. Concordance between the 2 geriatricians' clinical assessments was analyzed by kappa statistics. Excellent concordance was found; therefore, the first geriatrician's decisions were accepted as the gold standard. The correlation of nutrition status of the patients, determined with NRS-2002 and experienced geriatrician's decisions, was evaluated for the validity. Results NRS-2002 has a sensitivity of 88% and specificity of 92% when compared with professional assessment. The positive and negative predictive values were 87% and 92%, respectively. Testretest agreement was excellent as represented by a kappa coefficient of 0.956. Conclusions NRS-2002 is a valid tool to assess malnutrition risk in Turkish hospitalized patients.