Using incidence data from three national cancer surveys and mortality data for the entire United States, one can make several observations concerning the trends in cancer occurrence. Rates among males have been increasing, whereas those among females have been decreasing. In the past, cancer of all sites combined occurred more frequently among females; now males have rates higher than do females of the same race. White predominance has been replaced by a nonwhite excess in incidence and mortality rates among males and a nonwhite excess in female mortality; racial differences in incidence rates among females have been diminishing. Increases have occurred in cancers of the lung, prostate gland, breast among nonwhite females, pancreas, kidney, bladder among males, and esophagus among nonwhites; melanomas have increased among whites, and lymphomas have increased in each race-sex group. The reported increases may be due partly to improvements In diagnosis, which probably varied for the different primary sites and probably affected nonwhites more than whites. Meanwhile, decreases have occurred in cancers of the uterus (particularly cervix), stomach, and liver. Intestinal cancer has increased, whereas rectal cancer has decreased. Possible problems in specifying the site of origin of tumors arising in the area of the rectosigmoid junction make it difficult to determine how accurately the observed trends reflect the true situation. When intestinal and rectal cancers are considered together, the rates for nonwhites have been increasing toward the more stable level of the whites. The incidence of thyroid cancer has increased, whereas the mortality has decreased. Without lung cancer, the incidence of all cancer types combined among white males would be decreasing in recent years rather than increasing. The increases in overall incidence seen among nonwhite males are due primarily to increases in cancers of the lung, prostate gland, intestine, and esophagus. Among white females, the decrease in overall incidence is due to the decreases in cancers of the uterine cervix and the stomach; breast cancer rates are steady and continue to have a major impact. Except for breast cancer, the experience of nonwhite females is similar, with the declines in uterine cancer being greater and those in the other sites being less than the declines observed for white females.