In a population of almost 184,000 prospectively studied participants, the risk of lung cancer was ascertained according to the level of cigarette smoking and ethnic or racial background. Among those who smoked no more than 30 cigarettes per day, the relative risk of lung cancer was highest among African Americans and native Hawaiians, as compared with whites, Hispanics, and Japanese Americans. Among those who smoked no more than 30 cigarettes per day, the relative risk of lung cancer was highest among African Americans and native Hawaiians, as compared with whites, Hispanics, and Japanese Americans. The incidence of lung cancer is substantially higher among blacks, Native Hawaiians, and other Polynesians and lower among Japanese Americans and Hispanics than among whites in the United States. 1 The vast majority (80 to 90 percent) of these cases are attributable to cigarette smoking. Smoking behavior also varies widely among these ethnic and racial groups. In aggregated population surveys conducted in the United States, the age-adjusted prevalence of cigarette smoking was 30.1 percent among black adults and 27.3 percent among white adults. 2 Only 8.0 percent of black smokers, however, were reported to be heavy smokers (smoking at least 25 cigarettes . . .