The pathogens associated with ants at the teaching hospital of the Federal University of the Triângulo Mineiro, in Uberaba, MG, were studied. Three species of ants were identified: Tapinoma melanocephalum, Pheidole sp and Paratrechina longicornis. The principal microorganisms found were Staphylococcus sp, Gram-positive bacilli, Pseudomonas sp and Micrococcus sp. The results from the collections were analyzed according to the number of colonies and the different microorganisms isolated, using Student's t test. The statistical analysis showed that there was a significant difference only with regard to Staphylococcus sp. (p=0.005). It is possible that ants and pathogenic agents have mutualistic associations, and that analysis of such relationships may lead to new pest control strategies, with an emphasis not only on the insects but also especially on which agent is associated with these insect species.