A new species of the corydoradine catfish genus Aspidoras is described from an isolated coastal river basin in northeastern Brazil. The new species is the first record of a member of the subfamily Corydoradinae from the intervening region between the rio Jaguaribe and rio São Francisco basins. Aspidoras depinnai, new species, is distinguished from all congeners by the presence of distal bifid serrations on the ossified portion of pectoral-spine posterior border and an irregular arclike blotch on the caudal peduncle. It differs from the remaining Aspidoras species examined in the present study by the presence of an irregular row of minute pores on the head and a small cartilage between the upper principal and procurrent caudal fin rays.