The aims of the study were to investigate the relationship between nutritional state and the development of pressure sores and to test the hypothesis that supplementary nutritional support might prevent pressure sore development and improve healing. Newly admitted long-term care patients hospitalised for more than 3 weeks were included and randomised into an experimental and a control group. The nutritional state was evaluated using serum protein analyses, anthropometry and the delayed hypersensitivity skin test. Further, the patients' condition was assessed weekly using a modified Norton scale. The experimental group received extra nutritional support. Significantly more patients with protein-energy malnutrition had, or developed, pressure sores. Regression analyses indicated albumin, mobility, activity and food intake as predictors for pressure sores. Patients who received extra nutritional support tended to develop fewer pressure sores and to heal existing pressure sores to a greater extent than the control group, although this did not reach statistical significance.