Incidence was derived from published data from 2 population-based registries-the Philippine Cancer Society-Manila Cancer Registry and the 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 Civil 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 1988-1992 the combined age-standardized incidence rates (ASR) were 21.2 for male liver cancer (ranked second), and 7.3 in females (ranked seventh). Liver cancer rates for both sexes were higher than those observed among North American and European populations. Within the region, high rates were observed in both males and females in Thailand, Japan, China, Korea, Philippines, Singapore and Viet Nam. The rate begins to rise steeply at age-group 40-44 years among males and females. There were significant differences in rates between some cities and municipalities, with the rates in some areas double those seen in low incidence areas. Rates observed among Filipino migrants to the USA had decreased by around half of those seen among Philippine residents