The genus Diolenius Thorell is revised to include 14 species, 9 of them new to science. Diolenius carinifer Strand is synonymised with D. armatissimus Thorell. A female of D. armatissimus is described for the first time. Diolenius bicinctus Simon is considered nomen dubium. Four species: D. albomaculatus Thorell, D. bifasciatus Thorell, D. venustus Thorell and D. vittatus Thorell hitherto included in Diolenius are transferred to Ohilimia. For D. phrynoides a neotype specimen is designated. All species of Diolenius sensu stricto are diagnosed, described and illustrated. A key to the species of Diolenius and distributional maps are provided. The genus is closely related to Clialcolecta Simon, 1884 and Ohilimia Strand, 1911 and its range is restricted to rain forests of New Guinea, New Britain, The Moluccas and some adjacent islands.