There exists an imperative to monitor changes in body composition in all dialysis patients on a regular basis to avoid overt malnutrition. In this regard, the absolute measurement of the fat-free mass assessment may not be as crucial as the serial measurement of fat-free mass with the same modality. A significant difference in measured fat and fat-free mass should be expected if different techniques are employed. Therefore, when attempting to monitor patients over time or to assess the effects of changes in therapeutic regimens, a single methodology should be employed. Our data validate the use of BIA in the stable PD patient, indicating that BIA can predict the DXA results. Considering the ease with which BIA measurements can be obtained and the lack of dependency on operator interpretation, BIA is an ideal technique for use in the clinical setting. The applicability of this technique for use in monitoring longitudinal changes in body composition has, in fact, been well established (25, 30, 31). BIA appears to be an excellent method for routine fat-free mass measurement in dialysis patients. In as much as malnutrition continues to remain a significant problem in PD patients, measuring and monitoring body composition is strongly recommended.