Summary A survey of serum albumin and caeruloplasmin variants in populations of Australian Aborigines, Australian Caucasian, South African Bantu, Indians and New Cuinea indigenes has been carried out. One serum albumin variant in 595 samples from New Cuinea was detected. The variant phenotype contained a band migrating more rapidly than normal phenotype but more slowly than the Albumin Naskapi. It is provisionally identified as Albumin New Cuinea in accordance with the usage of Weitkamp, Shreffler and Saave (1969). No serum albumin variants were found in the other populations sampled. Caeruloplasmin variation was common amongst Bantu, rare amongst Aborigines and absent in Indians, Caucasians and New Guinea indigenes. The frequency of the CpA gene was 0·035 in Bantu and 0·002 in Aborigines.