Blood specimens were sent from New Guinea to the Serological Population Genetics Laboratory, London, and tested for blood groups, serum groups and red-cell isoenzymes. The tests carried out are listed but the results are described separately in this volume (by Booth). The general distribution of blood groups and other factors in the region as a whole, is described. They can mostly be explained by assuming the very early settlement of human populations in Australia and New Guinea, followed by the more recent migration of peoples from southeast Asia into most of the islands, but only to the coastal areas of New Guinea and hardly at all to Australia.