ABSTRACT: Arboviruses are agents transmitted by arthropods and represent a considerable threat to public health worldwide, causing diseases in humans and animals. A serological investigation was carried out to detect total antibodies against different types of arboviruses in free-living coatis (Nasua nasua) from the Iguaçu National Park (INP) through the Hemagglutination Inhibition test. Serum samples were tested using antigens from 33 arboviruses belonging to the genera Alphavirus, Flavivirus, Orthobunyavirus, and Phlebovirus. The data showed that 23.6% (17/72) of coatis were seropositive for at least one of the tested antigens, including monotypic and heterotypic reactions. Seropositivity was detected for Alphavirus (5.9%, 1/17; WEEV), Flavivirus (64.7%, 11/17; YFV, ILHV, SLEV, BSQV, ROCV, WNV, DENV-1, DENV-2, DENV-3, DENV-4, and NJLV), Phlebovirus (88.2%, 15/17; ICOV and BUJV) and Orthobunyavirus (5.9%, 1/17; ORIV). The presence of antibodies to these viruses in coatis from INP indicated an apparent silent circulation of arbovirus, implying N. nasua to be a possible amplifying host of these arboviruses in the studied area. The data reported also serve as a warning about the possible risk of establishing an arbovirus transmission cycle involving vector arthropods and coatis, or even other wild animals, consequently, including humans in this transmission chain.