Trends in cancer incidence and mortality in the United States were analyzed over the period 1969 through 1976. The greatest increase in incidence among whites occurred for lung cancer among females (almost 9%/yr), whereas the incidence of cancer of the uterine corpus increased 6% per year. Cancer of the cervix showed the greatest decrease in incidence, an average of 6% per year. Stomach cancer incidence and mortality showed a substantial decline for each sex, and rectal cancer incidence increased for each sex whereas mortality declined. The incidence of cancer of the female breast increased 1.8% per year without inclusion of the rates for 1974 and 1975, when an unusually large increase occurred. Cancer mortality data were presented for the total United States on the basis of data from the National Center for Health Statistics. Emphasis was focused on the comparability of cancer incidence data over the time period studied, given the fact that cancer incidence was measured by the Third National Cancer Survey for the period 1969-71 and by the Surveillance, Epidemiology, and End Results Program for the period 1973-76. Each survey covered approximately 10% of the U.S. population but had four geographic areas in common. Investigation of the comparability of these two surveys revealed that the incidence rates for whites were sufficiently comparable to permit an analysis of trends in cancer incidence over the entire period 1969-1976. Such comparability was not found for blacks. Therefore, cancer incidence data are presented only for whites, but cancer mortality data are presented for both whites and blacks.