Esco, MR. The accuracy of the body adiposity index for predicting body fat percentage in collegiate female athletes. J Strength Cond Res 27(6): 1679–1683, 2013—The body adiposity index (BAI) is a new simplistic method for predicting body fat percentage (BF%) via a simple equation of hip circumference to height. A scientific study of this novel method in athletic groups is warranted because of the possibility of it serving as an inexpensive field technique. The purpose of this study was to cross-validate the BAI for predicting BF% in a group of collegiate female athletes by using dual-energy x-ray absorptiometry (DXA) as the criterion variable. Thirty college-aged female athletes (age = 20.0 ± 1.3 years) participated in this study. For each participant, BF% was obtained with the BAI method and compared with DXA. The mean BF% was 27.1 ± 3.4 by the BAI and 26.7 ± 5.9 from DXA, which was not significantly different (p > 0.05). However, the BAI did not provide a significant correlation with the DXA (r = 0.28, R2 = 0.08, p > 0.05) and resulted in a standard error of estimate = 5.78% and total error = 5.84%. Bland-Altman plot showed that the limits of agreement (95% confidence intervals) between the DXA and BAI ranged between −10.2 and 11.8%, and there was a significant negative association between the difference and mean of the 2 methods (r = −0.52, p < 0.01). The results of this investigation indicate that BAI results in large individual errors when predicting BF% in female athletes and has a tendency to provide overestimated values as BF% decreases. Therefore, this method should not be used for predicting individual BF% in athletic women.