The taxonomy of the genus Phenacogaster is reviewed in Colombia, and nine species are recognized in the country. This study includes the description of four new species using morphological data. The new species are: Phenacogaster yari, new species, from the Amazon River basin that differs from its congeners by the combination of an incomplete lateral line, the relative posterior position of the humeral spot, 29–32 branched anal-fin rays, six gill-rakers on the lower limb of the first gill arch, presence of bony hooks on pelvic-fin rays of males, absence of hooks on pectoral-fin rays of mature males, and a relatively shorter standard length (adult males with 25 mm SL); Phenacogaster nukak, new species, from the Orinoco River basin that differs from the other species by the combination of an incomplete lateral line, humeral spot far from the psedotympanum, 8–11 perforated scales in the lateral line, 29–30 teeth in the maxilla, 32–34 branched anal-fin rays, body height 28.8–43.3% SL, and pre-ventral length 37.4–41.7% SL; Phenacogaster tukano, new species, from the Amazon River basin that differs from the other species by the posteriorly displaced humeral spot and a complete lateral line; and Phenacogaster guayupe, new species, from the Orinoco basin is recognized by an incomplete lateral line, a large and round humeral spot near the pseudotympanum in females with width greater than half the ocular diameter, 2–3 large tricuspid teeth in the outer row of the premaxilla, and a pre-ventral length 36.4–43.3% SL. A taxonomic key for the identification of species is provided, together with distribution maps of all species in the genus in Colombia.