Incidence was derived from published data from 2 population-based registries-the Philippine Cancer Society-Manila Cancer Registry and Department of Health-Rizal Cancer Registry, which covered 8.5 million residents (1990 census) of a 1,674 square kilometer area that comprises Metro Manila and Rizal province. Thirteen registry clerks actively sought new cancer cases in 96 hospitals and 30 Covil Registry offices. Both registries are members of the International Association of Cancer Registries and receive continuing professional assistance from the International Agency for Research on Cancer (IARC). For the period of 1988-1992 the combined age-standardized incidence rates (ASR) were: 6.8 for male nasopharynx cancer (NPC) (ranked sixth) and 3.2 among females (ranked thirteenth). NPC for both sexes were highest among Asian populations. Within the region, Philippine rates were third highest, following the Singapore Chinese and Vietnamese. Age-specific rates in males reached 10 per 100,000 at age-group 40-49 years, and 5 per 100,000 females at age-group 45-49 years, continuing to rise with increasing age. There were some significant differences in ASRs between some cities and municipalities but the differences were more striking among males as female rates were lower. Rates had increased only very slightly in the 13-year period between 1980-1992 but total cases had triples. NPC ASRs among male Filipino migrants to the USA were only half of that observed in Philippine residents, but were still higher than the rates among White residents. A similar decrease was seen among female migrants, and in Los Angeles the rates of Filipinos and non-Hispanic White females were already similar