Urea kinetic modeling (KM) permits the calculation of urea volume (VKM), urea generation rate (GKM), and normalized protein catabolic rate (nPCRKM) but requires complex, iterative calculations. Simpler methods for estimation of these parameters (Vest, Gest, nPCRest) were compared with those obtained from kinetic modeling. Kinetic modeling was performed on 17 patients using the 3 BUN method, producing 19 data sets. All were within 25% ideal body weight and all had less than 20% difference between VKMand Vesl. Vestwas estimated as 0.195 (height) + 0.296 (weight)–14.01. Gestwas estimated, using interdialytic changes as: (BUN change±Vest) + (wt change)±(pre BUN) + U/Interdialytic interval where U is urinary urea excretion rate. nPCRestwas estimated as: (Gest×9.35) +(0.294±Vest)±(0.58/Vest) There was no significant difference (Student's t text) between mean±SD Vest(41.24±3.86 L) and VKM(40.71±5.24 L), Gest(7.23±1.92 mg/min) and GKM(7.04±2.10 mg/min), and nPCRest(1.12±0.24 g/kg/day) and nPCRKM(1.10±0.23 g/kg/day). Correlation between Vestand VKMwas poor (r2-0.56, slope = 0.41). Correlations between Gestand GKMand nPCRestand nPCRKMwere good (r2= 0.95, slope = 0.87; and r2= 0.99, slope = 1.02, respectively). Conclusion: Assessment of nutritional status using Gestand nPCRestcan be carried out with high degree of accuracy even if Vestand VKMare not identical.