Ticks are ectoparasites of worldwide distribution that affect vertebrates and can transmit pathogens to animals and humans. The Zoological Park Foundation of São Paulo (FPZSP) is located in a Conservation Unit in one of the most important remaining fragments of the Atlantic Rainforest biome in the suburbs of São Paulo, Brazil. The FPZSP houses more than 3,000 wild animals on exhibit, in breeding programs and in environmental education programs, and also attracts migratory birds and free-roaming wildlife. This study focused on identifying the diversity of tick species that infest captive and free-roaming animals at the FPZSP. The collection of ticks kept at the FPZSP contains 523 specimens that were collected from different host species between 1990 and 2017. Ten tick species were found. In addition, Amblyomma aureolatum (Pallas) was found on stray cats living in the Atlantic forest fragment in the FPZSP. This study reveals a low occurrence of parasitism in captive animals and a high diversity of tick species collected from hosts in this Atlantic forest fragment, contributing information about host-parasite relationships and potential vectors of zoonotic diseases, since the vectors of Brazilian spotted fever, A. aureolatum and Amblyomma sculptum Berlese, were found in some hosts.