“Grass-fed” livestock products are advertised as having greater nutritional benefits than conventional livestock products. This study examined concentrations of vitamin A, vitamin E, carotenoid and fatty acids in pastured and conventional ground beef available to consumers. We hypothesized that ground beef finished on fresh pasture will have greater amounts of fat-soluble vitamins and omega-3 fatty acids than beef fed grain and stored feeds. Ground beef samples were collected once in summer and once in fall 2006 from producers that used pasture and/or stored feeds to finish beef. Summer samples included beef from 26 Pennsylvania producers: 14 finished beef on pasture; 5 finished on combinations of grain, and corn and hay silage; 7 finished on fresh pasture and some hay, baleage, or sorghum greenchop. Fall samples included beef from 24 PA producers: 12 finished beef on pasture; 6 finished on combinations of grain and baleage; 6 finished on a combination of pasture and hay, baleage, or sorghum greenchop and some grain. Six beef samples from Midwest feedlots were collected at local processors and markets in summer and fall. Pastures were sampled for botanical composition once in summer and revealed cool-season grasses as the primary forages, including orchardgrass, quackgrass and Kentucky bluegrass as the dominant species, with contributions of timothy, tall fescue, perennial ryegrass and various weedy grasses. Beef fatty acids and vitamins will be extracted using a saponification protocol. Fatty acid profiles will be determined using gas chromatography, and vitamin A, vitamin E and carotenoid content will be determined using high performance liquid chromatography. Data will be evaluated using analysis of variance and regression in SAS, and results will be reported.