High levels of microbial contamination, commonly found in animal origin foods and food processing environments, are able to hinder the growth of pathogens in these products and interfere in the results of laboratory analyses for detection of these pathogens. With the aim of verifying the possible interference of the autochthonous microbiota encountered in meat and meat products and processing plants over the presence of Listeria spp., 443 samples, collected from 11 meat retail establishments, were submitted to microbiological analysis to determine the levels of mesophilic aerobes, total coliforms and Escherichia coli and the presence of Listeria spp., according to the methodology proposed by the USDA. The results did not show evident interference of the autochthonous microbiota over Listeria spp., once the genus was detected even in the meat, meat products and environmental samples with high levels of contamination by mesophilic aerobes and coliforms.