Dialysis must control the bodys fluid content accurately in order to maintain optimal health. Determination of body hydration and nutritional status are significant problems in dialysis patients. In practice, clinical evaluation is usually used to estimate the ultrafiltration target, since accurate knowledge of dry weight is lacking. PD over-hydration is more common than in HD. The only commonly used, practical and objective measurements we have to guide fluid removal are very inaccurate. Several methods have been proposed for non-clinical dry weight assessment; unfortunately these methods suffer from several shortcomings, such as poor specificity (natriuretic peptides), operator dependence (inferior vena cava diameter measurements) and poor correlation with extra cellular volume (continuous blood volume measurement). Recent study has validated bioimpedance (BIA) as an objective measure of fluid and nutritional status in dialysis patients. There are a number of different methods suitable for routine use available to the clinician. This review analyze the role of the different BIA techniques in peritoneal dialysis.