The nutritional status of 91 patients on four ptychogeriatric wards was assessed by anthropometricmeasurements and determination of circulating proteins. The patients had low mean values forweight, arm muscle circumference, plasma albumin and serum transferrin. Indicators of malnutrition were combined to define the nutritional status in each individual. Energy and/or protein undernutrition was found in 30% and obesity in 4%. Energy undernutrition was more common than protein deficiency. Undernutrition was quite common during the first year of hospitalization and did not correlate with the duration of hospital stay. Subjects with their own teeth had a lower prevalence of undernutrition than edentulous patients. Food intake was similar in patients with and without undernutrition. The possible interactions between malnutrition and chronic psychiatric disorders in the elderly are discussed.