Cancer incidence rates were compared for Filipinos in Hawaii (1978-81) and Manila (1977). Data for Hawaii were from the statewide Hawaii Tumor Registry; those for Manila were from the Central Tumor Registry of the Philippines. In addition, time trends (4-yr intervals) for cancer among Filipinos in Hawaii were examined for the period 1962-81 and compared with corresponding patterns among Caucasians. For most cancer sites, the rates among Filipinos in Hawaii showed expected increases or decreases from the Manila rates. Notable findings included a dramatic increase in thyroid cancer rates among Filipino women in Hawaii (highest of all ethnic groups), a surprising lack of increase in female breast cancer rates in Hawaii, and a lower than expected increase in colon cancer rates in Hawaii. The time trend analyses showed remarkably similar patterns in Filipinos and Caucasians in Hawaii and no suggestion that differences between the 2 populations are decreasing over time. These observations indicate that useful clues to cancer etiology can be found by further study of the Filipino experience in Hawaii.