The cyprinid genus, Oxygaster van Hasselt, 1823, is the name-bearing type genus of the family-group name Oxygastri Bleeker, 1860, which predates many of the commonly used family-group names for the family Cyprinidae. Historically, the phylogenetic position of Oxygaster within the cyprinid phylogeny has been poorly understood, resulting in an uncertain status for its associated family-group name. The phylogenetic placement of Oxygaster and the status of the family-group name Oxygastri are examined herein using sequence data from four loci: two mitochondrial (cytochrome b, cytochrome c oxidase I) and two nuclear (opsin, recombination activating gene 1). A combined data matrix of 4117 bp for 109 taxa was collected and analyzed. Our results recovered Oxygaster within a large and taxonomically disorganized clade, one that has been reported in other studies on the Cyprinidae. The position of Oxygaster has wide-ranging consequences which led us to synonymize a number of cyprinid subfamilies and reorganize the current cyprinid classification. We recognize a monophyletic Oxygastrinae Bleeker, 1860 that includes the following genera: Aphyocypris, Candidia, Ctenopharyngodon, Culter, Hemigrammocypris, Hypophthalmichthys, Ischikauia, Macrochirichthys, Megalobrama, Metzia, Nicholsicypris, Nipponocypris, Ochetobius, Opsariichthys, Oxygaster, Parachela, Paralaubuca, Pararasbora, Parazacco, Squaliobarbus, Xenocyprioides, Xenocypris, Yaoshanicus, and Zacco. We place the following family-group names into the synonymy of Oxygastrinae Bleeker, 1860: Cultrinae Kryzhanovsky, 1947; Hypophthalmichthyinae Günther, 1868; Opsariichthyinae Rendahl, 1928; Squaliobarbinae Howes, 1981; and Xenocypridinae Günther, 1868.