This essay aims to present some sexual representations in rock art in the Serra da Capivara National Park (PNSC), in southeastern Piauí, Brazil. Since immemorial times, humans have created ways to express themselves, and rock art, engravings and/or paintings were sociocultural forms found to store and safeguard the most varied everyday information of group interests. More than 1,000 archaeological sites are known in the park, representing subjects related to the sociability of ancestral life, such as hunting, gathering, fighting, ceremonies, sexualities and much more. These depictions have been studied since the 1970’s and allowed the creation of a national park recognized as a World Heritage site. Although the paintings depict scenes considered by Western observers as obscene, barbaric and immoral, it is necessary to remember that primitive sexuality was not separate, private subject, to be hidden from the eyes of the social human life, as it is considered by us in 21st century. Key words: sexuality, rock art, prehistoric life, Serra da Capivara National Park, Piauí.