Objective Autosomal dominant polycystic kidney disease (ADPKD) patients with massive organomegaly suffer from pressure-related complications including malnutrition. In this study, we analyzed the efficacy of segmental bioelectrical impedance analysis (BIA) for objective and quantitative nutritional assessment in ADPKD patients Design and methods We conducted a cross-sectional study, to evaluate the clinical utility of segmental BIA for assessing the nutritional status of ADPKD patients. BIA measurements was assessed according to modified subjective global assessment (SGA) scores and were compared with data from a healthy population. The association between BIA measurements and the height adjusted kidney and liver volumes (htTKLV), were analyzed. Subjects A total of 288 ADPKD patients, aged 18 years old, were analyzed Main outcome measures Nutritional status was evaluated with SGA and segmental BIA. The htTKLV were measured in each patients using computed tomonography images. Results Higher ratios of extracellular water to total body water (ECW/TBW) in the whole-body (ECW/TBW WB ), trunk (ECW/TBW TR ), and lower extremities (ECW/TBW LE ) and lower phase angle of lower extremities (PhA LE ) correlated with lower SGA scores in the ADPKD population and in both gender. The four parameters, ECW/TBW WB , ECW/TBW TR, and ECW/TBW LE of >0.38 and PhA LE of <5.8 θ were associated with malnutrition in ADPKD patients. These correlations were preserved in the subgroup analysis for chronic kidney disease stages 1-3A. Compared to healthy populations’ data, body fluid parameters and segmental ECW/TBW values, except for the upper extremities (ECW/TBW UE ), were greater in ADPKD patients. Increased htTKLV was an independent risk factor for malnutrition in ADPKD. The highest correlation with htTKLV was observed for the ECW/TBW TR (r = 0.466), followed by ECW/TBW WB (r = 0.407), ECW/TBW LE (r = 0.385), PhA LE (r = -0.279), and PhA TR (r = 0.215). Conclusions These results demonstrated that segmental BIA parameters of ECW/TBW WB , ECW/ TBW TR , ECW/TBW LE and PhA LE provide useful information on nutritional status including the impact of organomegaly in ADPKD.