The aim of this study was to assess the usefulness of a Multidimensional Prognostic Index (MPI) based on a Comprehensive Geriatric Assessment (CGA) in defining comorbidity and the need for a multidisciplinary approach in older patients with end-stage renal disease. This was a cross-sectional study that included 162 patients, 103 aged 65 and over with a diagnosis of end-stage renal disease and ongoing chronic hemodialysis treatment. Results were compared with a group of 250 geriatric patients without renal impairment. A standardized CGA that included information on clinical, cognitive, functional and nutritional aspects, as well as comorbidity, medications and social support network, was used to calculate MPI. Among the dialysis patients, the vast majority showed a moderate (58.3%) or high risk score (19.4%). MPI score was clearly correlated with Charlson index (P = .001) both in the global population and the dialysis patients aged over 65. Compared to geriatric patients without renal failure, all MPI score domains were more compromised in the dialysis population. These preliminary findings strongly suggest that MPI may be very useful to assess the clinical picture of older patients undergoing renal replacement therapy (RRT). Its use in the dialysis population under 65 needs to be investigated.