Pilosocereus oligolepis is a species of Cactaceae that is known only from three old type collections in Brazil (Roraima state) and Guyana. It is the only species of this genus to occur in northern Brazil. Due to the paucity of specimens and lack of precise locality data we undertook fieldwork in different vegetation types of Roraima aiming to find the species in the field. Populations of P. oligolepis were found in two previously unknown areas, occurring on granitic rock outcrops inside a vegetation mosaic of seasonal forests and savannas. Thus, it was possible to expand our knowledge of this species, increasing its occurrence and distributional data, as well as to provide pictures of the plants in their habitat and propose an updated conservation status.