Producing beef on natural grasslands may represent an alternative to local farmers to add value on meat products of Pampa Biome. However, the quality characteristics of these products must be investigated. In this sense, we investigated the meat quality of three grazing-based beef production systems in Pampa biome: Natural grassland (NG), Improved natural grassland (ING, fertilized and oversown with winter species) and Sorghum pasture (SP). From December, 2009 to November 30, 2010, we studied 43 Aberdeen Angus steers of about 18 months of age and 320 kg of body weight which were randomly distributed between treatments: NG (n=16); ING (n=18); SP (n=8). Animals were slaughter at 3 mm of fat thickness (FT). We evaluated steers performance and meat quality traits of beef. There were found perceptible differences on flavor and odor between the feeding systems. Beef from NG was tougher than that from SP, mostly because lower gains obtained on NG, however more desirable fatty acid profile was found for beef from animals grazing NG and ING.