Investigations on the microflora of the Brazilian cockroach Blaberus giganteus L. were done in order to estimate its role as a vector of pathogenic agents. The isolated microorganisms refer mainly to the following groups: the family Enterobacteriaceae Salmonella entericа, Enterobacter aerogenes, Serratia liquefaciens, Hafnia alvei and the genera Pseudomonas Р. solanacearum, P. aeruginosa, Staphylococcus S. xylosus, S. haemolyticus, S. hominis, Enterococcus, Bacillus, Clostridium and Listeria. The established fungi are from the genera Fusarium, Aspergillus и Candida С. albicans. The results of the investigations show that the cockroaches from this species might be a reservoir and spreader of causal agents of infections not only among the animals and humans, but among the plants too.