Objective: The aim of the study was to identify the most significant MNA-items to accelerate the determination of nutritional risk of elderly patients in routine clinical practice in a geriatric hospital. Since MNA requires 10–15 min it is hardly applicable to clinical routine.Design: The study was a cross-sectional study. Setting: The study centre was an acute geriatric hospital. Participants: In total 808 multimorbid elderly patients were recruited. Methods: We applied the MNA in 808 (528f/280m) geriatric multimorbid patients (78.5 ± 8.7f / 74.6 ± 9m yrs) without cognitive impairment 48h after hospital admission. Admission diagnoses covered orthopaedical (40%), internal (34%) and cerebrovascular (24%) diseases. According to analysis of reliability the consistency of the MNA scale for multimorbid patients has been verified. In preparation for scale reduction a factor analysis was applied. A reduced scale with selected cutoffs was configured and compared with MNA.Results: According to MNA, 15% of patients were well-nourished, 65% at risk of malnutrition and 20% were malnourished. The reliability analyses showed a Cronbach's Alpha of 0.60 that represented a satisfactory result. By means of factor analysis the MNA-items were reduced from 18 to 7 items (weight loss, mobility, BMI, number of full meals, fluid consumption, mode of feeding, health status), with new cutoffs (12.5–15 well-nourished, 9–12 at risk of malnutrition, <9 malnourished). According to the modified MNA (m-MNA) 21.7% of the patients were well-nourished, 54.5% at risk of malnutrition and 21.7% were malnourished. The score of the MNA and m-MNA correlated with r=0.910. Furthermore, there was a strong correlation between MNA and m-MNA group classification of 83%.Conclusion: The m-MNA enables a rapid (3min) and efficient screening of malnutrition in multimorbid geriatric patients. The m-MNA is easy to apply and may also be suitable in multimorbid patients with cognitive dysfunction. Due to the variety of items the m-MNA seems to be superior to other screening tools.