BACKGROUND: The evaluation of nutritional status is one of the primary components of multidimensional geriatric assessment. We investigated the relationship between some markers of malnutrition and the modifications in functional status in a sample of older disabled residents living in nursing homes. METHODS: Ninety-eight subjects who were independent in at least two activities of daily living (ADLs) were enrolled in a 2-year longitudinal study. Anthropometric, nutritional, and metabolic parameters, as well as body composition, were measured at baseline and after 2 years. RESULTS: Deteriorating functional status (> or =2 additional lost ADLs) was associated with baseline albumin levels (Tertile 3 vs Tertile 1; odds ratio [OR] 0.16, 95% confidence interval [CI] 0.04-0.67) and subscapular skinfold thickness (Tertile 3 vs. Tertile 1; OR 0.06, 95% CI 0.006-0.50). After multivariate adjustment, the OR for increasing disability was >4 in subjects with decreasing body cell mass (BCM), compared with subjects with a stable BCM. The degree of BCM reduction was strongly related to the number of additional ADLs lost at follow-up (test for trend, p = .003). CONCLUSIONS: In a sample of older disabled nursing home residents, signs of malnutrition seem to predict further worsening in functional status. Furthermore, BCM declines proportionally to the loss in ADLs, suggesting the existence of a strong relationship between BCM loss and the progressive deterioration of functional status.