This work reports the tick species collected from June 2000 to June 2004 from six small red brocket deer (Mazama bororo), a recently discovered deer species, and one gray brocket deer (Mazama gouazoubira), all free-living in an Atlantic rain forest area in São Paulo State, Brazil. The small red brocket deer were infested with larvae, nymphs and adults of Haemaphysalis juxtakochi, nymphs of Amblyomma incisum, and several undetermined Amblyomma nymphs and larvae. The gray brocket deer was infested with A. incisum nymphs and undetermined Amblyomma nymphs. A gray brocket deer carcass found 3 km away from the forest had 12 nymphs of Amblyomma cajennense. Haemaphysalis juxtakochi has been commonly found on deer species in the Neotropics, suggesting a natural host-parasite relationship. Amblyomma incisum is a tick from dense forest habitats and its principal hosts, tapirs, probably maintain tick populations along forest trails, with the result that immature stages infest deer sharing these trails. Amblyomma cajennense is a very widespread tick in Brazil, and its primary hosts are capybaras, tapirs and horses. An interesting feature of this work was the absence of A. cajennense on forest deer.