Twenty-nine taxa of Eriocaulon L. are recorded in this synopsis of the genus for the region of New Guinea. A key to the New Guinea species is provided. The widespread E. cinereum R.Br. is not recorded for New Guinea but is included in the key. Eriocaulon brevipedunculatum var. longipes Moldenke is determined as a synonym of E. novoguineense P.Royen. Issues of lectotypification are discussed for E. echinulatum Mart. (syntypes identified), E. hamiltonianum Mart., E. hookerianum Stapf, E. nepalense var. luzulifolium (Mart.) Praj. & J.Parn., E. truncatum Buch.-Ham. ex Mart. Species with extra New Guinea distributions are E. australe R.Br., E. depressum R.Br. ex Sm., E. echinulatum, E. hamiltonianum, E. hookerianum, E. nepalense var. luzulifolium, E. setaceum L., E. sexangulare L., E. truncatum, E. willdenovianum Moldenke and E. zollingerianum Körn. A high level of endemism is recorded, particularly in the alpine zone.