This study tested the hypothesis that female white-tailed deer (Odocoileus virginianus) select a higher quality diet than males, as suggested by McCullough's (1979) evidence for resource partitioning between the sexes. Fecal samples from 136 adult female and 95 adult male deer were collected during 1982–83 on the E. S. George Reserve, Michigan. These fecal samples, and rumen and fecal samples from deer shot in winter 1980–81, were analyzed for winter diet composition by forage class, and for year-long diet quality as indexed by fecal nitrogen (FN). Year-round, females had significantly higher FN levels than males. In winter, females consumed significantly more grass and less browse than males. Thus, females consumed diets of higher quality than did males.