Resumo. Chigger mites are ectoparasites of terrestrial vertebrates and can even bite humans, causing lesions on their skins. The co-parasitism is gradually being reported for this family, and recent studies have highlighted this relationship worldwide. In Brazil, only some records of chigger species co-parasitizing rodents and lizards in the Pernambuco and Piauí States were done. The present study reports six co-parasitism situations in cricetid rodents collected in the Morro Grande Forest Reserve, Cotia Municipality, São Paulo State, Brazil.