One hundred thirty skinks representing 7 species of Sphenomorphus (Scincidae) from Papua New Guinea were examined for helminths: S. aruensis, S. cinereus, S. fragilis, S. nigriventris, S. pratti, S. maindroni, S. simus. Two species of Cestoda (Oochoristica javaensis, Ophiotaenia greeri), 1 species of Digenea (Saurokoilophilia kinsellai), and 13 species of Nematoda (gravid individuals of Abbreviata oligopapillata, Aplectana macintoshii, Aplectana novaeguineae, Cosmocerca zugi, Entomelas moraveci n. sp., Falcaustra papuensis, Meteterakis crombiei, Moaciria moraveci, Oswaldocruzia bakeri, Parapharyngodon maplestoni, Pseudorictularia disparilis, and larvae of both Abbreviata sp. and Riculariidae gen. sp.) were found. The new nematode species was described and 19 new host records are reported. Helminths of 17 species of Sphenomorphus from New Guinea Island are reviewed; 59% of identified helminth species were found to be endemic. Mean helminth species diversity per species of Sphenomorphus for the 17 species so far studied was 6.4 ± 0.9 SE (range 2–14).