A new species of dorylaimid nematode, Aporcelinus abeokutaensis sp. n., collected from a watermelon field in Nigeria, is described, illustrated and molecularly (D2–D3 28S ribosomal DNA) studied. It is characterized by its 1.18–1.52-mm-long body, lip region offset by weak constriction, 15.5–17.5 μm broad with perioral liplets, odontostyle 18–21.5 μm long at its dorsal side or 1.1–1.3 times the lip region diameter, neck 333–401 μm long, pharyngeal expansion occupying 45–51% of total neck length, uterus simple and 0.7–1.5 times the corresponding body diameter long, V = 48–53, tail conical with finely rounded tip (33–52 μm long, c = 26–41, c′ = 1.3–1.9) and a variably distinct dorsal concavity, and male unknown. Molecular analysis reveals that the new species grouped with other species of Aporcelinus in a highly supported clade, confirming the monophyly of the genus.