A technique for estimation of carcass fat levels in ruffed grouse (Bonasa umbellus) from wing fat levels is evaluated. The utility of this technique was investigated because many :Btate wildlife agencies annually collect grouse wings for purposes of age determination and hence wings are readily available. Mean wing fat (percent ether extract) levels were not significantly different than carcass fat levels in grouse collected in fall and winter. Significant differences were found between wing and carcass fat levels in spring (P < 0.10) and summer (P < 0.01) collected birds. Despite these differences, wing fat data from spring collected birds may be useful for prediction of carcass fat because of a high correlation coefficient (r = 0.82) between the two variables. A lower correlation coefficient (r = 0.68) indicated limited utility for this technique in summer. No significant differences in wing fat levels were found between air-dried and frozen wing samples. Recommendations regarding wing sample size are discussed.