Background/Aim. Risk factors for the intrahospital nutritional status worsening (NSW) have not been precisely defined in the literature. The objective was defining thoese factors among gastroenterological patients and defining the risk patients requiring a preventive nutritional therapy. Methods. In 650 gastroenterological patients, NSW was evaluated on the basis of reducing of the six parameters: body weight, body mass index (BMI), triceps skinfold thickness (TSF), midupper arm muscle circumference (MAMC), serum albumin level (ALB), and lymphocyte count (LYM). The influence on NSW was tested for 13 factors concerning characteristics of the patient, disease, and diagnostic procedures. Among the factors influencing significantly the NSW, primary and secondary risk factors were selected. After scoring of risk factors had been performed, the risk-score for NSW (RSNSW) was defined. The critical value of RSNSW which required preventive nutritional therapy was also calculated. Results. The incidence of NSW was in the range 29.2%−57.9%. The presence of general complications and severe disease activity were considered as primary risk factors, whereas malignant disease, age above 71, hepato-billiary tract involvement, hospitalization longer than 14 days, and mobility worsening were considered as secondary risk factors. The best predictive value for the NSW was proved for the RSNSW ≥ 6. Because of that, preventive nutritional therapy should be indicated in patients presenting with both primary risk factors or in patients presenting with one primary factor combined with three secondary risk factors at least. Conclusion. There are 7 risk factors for NSW in gastroenterological patients, but they are not of the same importance - two primary and five secondary risk factors can be differentiated. Preventive nutritional therapy is indicated only in patients having both primary risk factors or in those presenting with one primary risk factor combined with three secondary risk factors at least.