The requirement of metabolizable energy (ME) for maintenance was studied in 31 male pastel farm-raised mink. The procedure used was a body balance regression technique that included an initial baseline group, a group allowed feed ad libitum, and a group allowed feed at the level of 65% of average intake of the ad libitum animals. The requirement for ME was 147.8 +/- 6.06 kcal/wtkg 0.734/day. This value falls within the range of estimates of maintenance requirements noted for younger animals of other species, such as the rat, chicken, and calf. The relationships of the chemical composition of the body to functions of body weight were also examined. The composition of the mink body was closely related to the weight of the animal rather than to age or conformation, as has been noted in other species. However, the fat-free dry body of the mink contained more protein and less ash than any other species studied up to this point. On a percentage basis, protein was 87.29 and ash was 12.72. Protein in the fat-free body of other species range from 80 to 82%.