SINNING, WAYNE E. Anthropometric estimation of body density, fat, and lean body weight in women gymnasts. Med. Sci. Sports. Vol. 10, No. 4, pp. 243-249, 1978. Measurements from 44 highly skilled women gymnasts were used to evaluate previously derived equations for estimating body composition and to develop new equations by step-wise linear regression. True composition values were computed from body density (DB). Measures were taken of skeletal diameters (D), circumferences (C) and skinfolds (SF). Equations evaluated were those by Sloan et al. (23), F. Katch and Michael (15), Wilmore and Behnke (28), F. Katch and McArdle (18) and Weltman and V. Katch (26). With exception of the Weltman-Katch equation, correlations between true and estimated LBW's were high (.91 to .95) but underestimated true LBW 1.13 to 3.88 kg. Regression analysis suggested adjustment of ordinate values would give these equations acceptable accuracy for use with women gymnasts. New equations were derived from variables that had been selected by using factor analysis to minimize shared variance. Equations derived were DB = 1.024620 + .002024 Neck C − .001435 Supra-iliac SF - .001039 Juxta-umbilicus SF (R .806, ± .0061); Fat = .3798 - .5809 Neck C + .3253 Abdominal C + .3007 Supra-iliac SF + .2047 Juxta-umbilicus SF, (R .891, ± 1.29) and LBW = .3973 Height + .8357 Neck C + .4317 Shoulder C - 87.203 (R .923, ± 1.75).