This paper reports the evaluation tests on the reliability and validity of a three-dimensional (3D) laser body scanner for the estimation of body volume and percent fat. Repeated measures of body imaging were performed for reproducibility analysis. The validity of the instrument was assessed by the comparison of the measures of body volume by imaging to hydrodensitometry, and body fat was compared to hydrodensitometry and dual energy X-ray absorptiometry. Reproducibility analysis showed little difference between within-subjects measurements of volume (intraclass correlation coefficient (ICC)≥0.99 and p<0.01). Body volume estimations by laser body scanner and hydrodensitometry were strongly related (r=0.99 and p<0.01), and agreement was high (ICC=0.99 and p<0.01). Measurements of percent body fat also agreed strongly with each other between methods (ICC=0.86 and p<0.01), and mean percent fat estimates by body imaging did not differ from criterion methods (p>0.05). These findings indicate that the 3D laser body scanner is a reliable and valid technique for the estimation of body volume. Furthermore, body imaging is an accurate measure of body fat, as compared to dual energy X-ray absorptiometry. This new instrument is promising as a quick, simple to use, and inexpensive method of body composition analysis.