A first known extant Neotropical species of the atelestid genus Alavesia—Alavesia leukoprosopa, sp. nov.—is described from southeastern Brazil. The holotype (and only specimen so far) was collected with a Malaise trap in an area with strongly impacted semideciduous seasonal forest (dry forest) and open, entirely secondary vegetation. It was collected in mid spring, but has not been collected again so far. Alavesia leukoprosopa shares some derived features with the only two other extant species of the genus, known from the Brandberg Massif in Namibia, suggesting that all three extant species may compose together a small clade separate from the bulk of the Cretaceous diversity of Alavesia.