The aim of the study was to compare the results of body fat (in % and kg) measurements, obtained from 15 young non-obese adults (4 males, 11 females) with the use of different methods: Underwater Weighing (UWW) and Air-Displacement Plethysmography (BOD POD); Dual X-ray Absorbtiometry (DXA); Bioelectrical Impedance Analysis (BIA), 4 Skinfolds measurements and BMI related formula, and to assess their correlation with UWW as a reference. The most accurate and best correlated with the reference were BOD POD and DXA. BIA gave results similar to and correlated well with UWW. Results of anthropometric methods correlated less with UWW, but mean values were not significantly different from the reference.