A sample of 104 adults underwent testing of body composition by multiple frequency bioelectric impedance analysis (MBIA) under controlled conditions, by anthropometric methods (skinfold thicknesses and BMI) and by the urinary creatinine method. The statistical comparison of body composition parameters (Fat, FFM, TBW), estimated by different methods for the same subjects, pointed out significant differences in mean values. The precision of skinfold and MBIA measurements was evaluated by a second control measurement. Concerning the MBIA, the reliability increased with increasing frequencies. Nevertheless, measurement reliability is higher for skinfolds than for MBIA. Under the condition that there is a real anthropometric technical ability, we affirm that the body composition parameters may at present be better estimated by the skinfold method.