Chaetomys subspinosus (Olfers, 1818) or bristle-spined porcupine is a species of rodent restricted to the Atlantic Forest of the Eastern Coast of Brazil, vulnerable to extinction. Four specimens captured in the State of Espírito Santo, at the Biological Station of Santa Lúcia (EBSL) and at the State Park Paulo César Vinha (PEPCV), were examined for the presence of ectoparasites. One female and three males of Amblyomma longirostre were collected from a single C. subspinosus female in three independent captures carried out in 2004 at the EBSL. No ticks were found on bristle-spined specimens from the PEPCV. This constitutes the first report of A. longirostre infesting this rodent species in the State of Espírito Santo and reinforces that these mammals from the family Erethizontidae act as hosts for adults stages of this ixodic tick species.