A phylogenetic hypothesis of relationships within the callichthyid subfamily Corydoradinae is proposed based on 83 characters. The monophyly of the subfamily is well supported, as are those of two included genera, Aspidoras and Brochis. However, the monophyly of Corydoras, as traditionally defined, is not corroborated, with some of currently included species being more closely related to Aspidoras or Brochis than to nominal congeners. These conclusions contrast with a previous hypothesis, which considered Brochis and Corydoras as forming a monophyletic assemblage, with Aspidoras as its sister-group. A clade composed of Aspidoras and the species currently assigned to Corydoras, C. barbatus, C. macropterus, C. prionotus and Corydoras sp. A, is herein recognized based on the following characters: possession of anterior portion of frontal bone long, hypobranchial 2 well ossified, free margin of opercle angulated, epiphyseal branch of the supraorbital canal long, and ossified portion of pectoral spine reduced. The remaining corydoradines are grouped in a monophyletic assemblage with complex vertebra compact, posterior expansion of ceratobranchial 3 notched, presence of triangular dorsal lamina on anguloarticular, and medial expansion of coracoid exposed. A new classification is proposed to accommodate the monophyletic groups defined in the present study. Discussions about subgroups within each major clade are provided.