We studied for the first time a collection of 377 snakes assembled by Benoît Mys and Jan Swerts in Papua New Guinea (PNG) during 1982–85. The collection, stored at the Royal Belgian Institute of Natural Sciences (RBINS), contains specimens collected in rapid assessments of 45 mainland and island localities in Madang, East Sepik, West Sepik, and Morobe Provinces, and 8 localities from West New Britain and Manus Provinces. Thirty-three species from six families (Acrochordidae, Boidae, Colubridae, Elapidae, Pythonidae, Typhlopidae) were present in the collection, and we report a number of new morphological observations from unidentified Dendrelaphis, Tropidonophis, and Aspidomorphus, as well as from Stegonotus cf. parvus. We report 31 new island records for snakes. Combined with island distributional information extracted from literature and museum collections, we provide an updated overview of snake species occurrences on the islands off the north coast of PNG. The substantial contribution of a 30-yr-old museum collection to current knowledge of the snake fauna of northern PNG illustrates how poorly studied this region is and the extent of herpetofaunal work still required to uncover true snake diversity in PNG.