PURPOSE: The aim of this pilot study was to describe the hydration and nutritional status of a cohort of elderly dialysis patients and to explore the association between these parameters and the quality of life (QoL). METHODS: All patients over 75 years of age being in chronic dialysis by January 2008 at 3 dialysis units (n = 34) were asked to participate in this pilot study, 24 patients were entered. Hydration status was assessed by bioimpedance spectroscopy (BIS) and nutritional status by the subjective global assessment (SGA), BIS, anthropometric measures and biochemical parameters. Based on these assessments the patients were classified as being cachectic or not according to newly defined criteria. QoL was measured using the SF-36. RESULTS: The results showed cachexia in 6 (25 %), 37.5 % had a body mass index below 24, whereas according to SGA 91 % were malnourished. BIS showed low lean tissue index in 46 % and overhydration in 35 % of the patients. Compared to non-cachectic and normohydrated, cachectic and overhydrated patients reported consistently poorer QoL. For cachectic patients, the differences were clinically significant for all SF-36. BIS was easily applicable when used before dialysis. CONCLUSIONS: The high frequency of nutritional deficits in this study calls for more attention to nutritional status in elderly dialysis patients. There is a need for a general agreement on how nutritional status should be assessed and reported, both in clinics and in research.