Cancer risks were compared in the Japanese, Chinese, Hawaiian, and Filipino populations of Hawaii with those in the U.S. white population. The analysis used standardized incidence ratio(s) (SIR), based on the U.S. white incidence rates for 1970. In general, the risks for many major cancers in the Japanese, Chinese, and Filipinos were low in relation to U.S. whites, whereas those for Hawaiians were high. However, the SIR values for the various cancer sites and types varied considerably within each ethnic group. Ethnic-specific data on smoking, drinking, and dietary habits and on sociologic and demographic factors were examined in relation to the SIR findings. Some of the results were consistent with current etiologic hypotheses, whereas others suggested areas for further epidemiologic study.