Plesioptopoma curvidens is a new genus and species of hypoptopomatine loricariid from the upper Rio Paraopeba, a tributary to the Rio São Francisco in southeastern Brazil. Plesioptopoma is attributed to the hypoptopomatines based on five shared synapomorphies, and differs from all remaining members of the subfamily by having the premaxilla and dentary tooth series strongly curved mesially, in such a way that the mesial portion of the tooth series in both sides are turned and run parallel to each other, the caudal peduncle distinctly quadrangular in cross-section, and the anterior margin of the snout devoid of dermal plates.