To find reference total body water (TBW) values in healthy Korean adults, we performed single frequency bioelectrical impedance analysis on 2942 healthy adults and compared these data with those of normal western adults. Males were found to have greater TBW than females. Conversely, females were found to have greater percent fat (pFat) than males. In both sexes, body weight (BW) and TBW were significantly lower in age groups of < 30, 50 - 59, ≥ 60 years than in the 40 - 49 years age group. pFats were significantly higher in age groups of 50 - 59 and ≥ 60 years than in the 40 - 49 years age group. pFats were similar among age groups of < 30, 30 - 39, and 40 - 49 in both sexes. In all age groups, pFats were significantly higher in females than in males. TBW was significantly correlated with BW, height (HT), fat mass, and body mass index (BMI) in both sexes. There was a significant correlation between TBW and age in males(r=-0.15, p=0.00), but not in females (r=-0.02, p=0.45). On linear regression analysis, TBW values were independently associated with BW, HT and age in males and were independently associated with BW and BMI in females. In all age groups, Korean males and females had lower mean TBW than in Western populations. However, this difference was greater in males than in females. In summary, we represented the contemporary normal TBW data in healthy Korean adults. At present, there are no national reference data relating TBW in Korea. We hope the results of this study will be useful as the baseline data for the evaluation of hydration and nutritional status in healthy and ill adults, including end-stage renal disease (ESRD).