Forty samples of ground beef were taken at four supermarkets in the city of Piracicaba, SP. Total bacterial counts were determined using a produre recommended by the American Public Health Association; the plates were incubated at 32°C (48 hours). A modified procedure based on resazurin reduction for the determination of ground beef microbiological quality was studied. The results can be summarized as follows = 1) Total counts were generally higth, with several samples in the range 10(7) to 10(9) cells/gram; the average count was 3,0 x 10(7) cells/gram. 2) The differences between counts related to any two supermarkets were not statistically significant. 3) Resazurin reduction to colorless was significantly correlated with total bacterial counts (r=-0,91).