During recent expeditions to Surinam, large ichthyological collections have been made from nearly all river systems by several ichthyologists, one of which was the author. Because of new information provided by the especially rich collections of Corydoras, a revision of the Surinam species and subspecies of this genus was thought necessary. This revision is based on 5211 specimens belonging to seventeen species and subspecies of which seven are new to science, viz., C. bondi coppenamensis, C. guianensis, C. heteromorphus, C. octocirrus, C. oelemariensis, C. schwartzi surinamensis and C. saramaccensis. A key to the Surinam species is provided and the taxonomic value of several characters is discussed. The distribution of the different groups within the genus Corydoras is discussed and remarks on ecology and ethology of Surinam species are given.