This paper reports haptoglobin and transferrin typing of 2687 serum specimens from Melanesians of New Guinea and New Britain. The specimens were obtained from members of 27 different cultural and linguistic groups residing in over 100 different villages in six different administrative districts. They were divided among the Districts as follows: New Britain 821, Sepik 623, Morobe 349, Eastern Highlands 613, Southern Highlands 222, and Western Highlands 59.In addition serum haptoglobin levels, serum iron levels and total serum iron binding capacity have been determined on these subjects. In the field hemoglobin determinations, blood smears for examination for malaria parasite rates, and spleen palpations were done on a proportion of the subjects, mostly children under ten years whose sera have been examined in this study. These field and laboratory results are correlated with the transferrin and haptoglobin gene frequency findings.The available data on haptoglobin and transferrin types in Melanesia is limited almost entirely to small groups in certain areas of the highlands of New Guinea. taken from the same specimens whose clots were examined for bIood group studies which have been recently reported. Thus, detailed discussions of many of the populations under investigation, their linguistic and cultural affiliations, and their ethnic origins have been presented along with brief discussions of the medical problems in each area in a series of recent reports