The nutritional state of 482 out of 501 newly admitted elderly patients was assessed by anthropometry, serum protein analyses and the delayed hypersensitivity skin test (DH) on admission and after 8 and 26 weeks. The mean age of the women was 81.3 +/- 7.7 and of the men 77.9 +/- 9.3. Protein-energy malnutrition (PEM) was initially defined as three or more subnormal criteria, one in each of the three categories of measurement. The data was then reanalysed excluding anergy and using the two other criteria only. The prevalence of PEM on the first assessment was 28.5% and was 10% higher when anergy was excluded as a criterion. PEM was more common in women and increased with age. The anergic patients had lower mean values in serum protein and anthropometry than those with normal reactivity. Anergic patients had a higher mortality rate and more pressure sores than the reactive group. Nutritional supplementation was associated with an increase in skin reactivity.