A review of 99 species and subspecies of the genus Corydoras is given. The primary type-material is recorded together with additional type-specimens deposited in 22 different museum collections. Two neotypes and 22 lectotypes are designated. The species are arranged in five groups: 31 species in the punctatus-group, 11 in the barbatus-group, 25 in the aeneus-group, 8 in the elegans-group, and 19 in the acutusgroup. Measurements and counts of almost all primary typespecimens are tabulated. Ill-known illustrations of type-material are included.