An analysis of cancer incidence and mortality data indicated that cancer has become one of the five leading causes of death in many of the republics and territories in the South Pacific. The most developed areas had rates that exceeded world averages for malignant neoplasms of the lung, breast, and cervix uteri. The two existing cancer registries are in the Papua New Guinea and Fiji. These registries have documented a number of unusual patterns of cancer incidence that allow casual inferences to be made. Among these are the association of chewing betel nut and cancer of the mouth, and the finding of Burkitt's lymphoma in Papua New Guinea with the same epidemiologic features as in West Africa. These and a number of other unusual patterns of cancer occurrence underline the need and the special opportunities for cancer research in the South Pacific.