A developmental series of free embryos and larvae of the endemic cyprinid species Pseudophoxinus stymphalicus from Lake Trichonis (Greece) is described and illustrated, based on material from laboratory rearing of embryos hatched from wild-caught eggs. Morphological changes and the occurrence of important ontogenetic events are followed up to the time of metamorphosis. Characters of potential systematic value are indicated. The larvae are characterized by robust body shape, dark appearance and very weak development of the mediolateral row of melanophores, and immediately distinguishable from the other cyprinid larvae of the lake.