Bioelectrical impedance methods have been found to be a valid and reliable way of estimating per cent body fat (%BF) in adults. We applied them to healthy children and compared them with conventional anthropometry methods. One thousand two hundred and sixteen children participated in this study. Impedance and skinfold thickness were measured, and %BF was estimated using these values. Bodyweight and height were measured, and per cent obesity (%OB) and body mass index (BMI) were obtained. The values of %BF by the bioelectrical impedance method (%BFi) were 8.6 +/- 4.0% in the junior male group, 14.2 +/- 2.8% in the junior female group, 7.9 +/- 4.7% in the senior male group and 16.1 +/- 2.9% in the senior female group. The %BFi correlated strongly with skinfold thickness, %OB and BMI. Thus %BFi correlated strongly with variables from conventional methods. It was concluded that it is a reliable way of assessing lipid storage in children.