The age-adjusted death rate from cancer peaked in the U.S. in 1990, and has declined steadily since then. We assess reasons for this progress by examining trends in cancer mortality by age, gender, and cause, using underlying cause mortality data from the Centers for Disease Control. Mortality rates for 2000 were estimated using models based on 1979 through 1997 mortality data. Indirect standardization was used to calculate the expected number of cancer deaths in 2000, by age, gender, and cause, assuming that the rates in 1990 had not changed. In the U.S. in 2000, there were an estimated 500,000 deaths from cancer; 64,000 (12.7%) fewer than expected, with 51,900 fewer cancer deaths among men and 12,200 fewer deaths among women. The decline in deaths among men resulted from fewer deaths from lung cancer (20,800), colon cancer (6,700), and prostate cancer (12,900). The decline in deaths among women resulted from fewer deaths from breast cancer (11,100) and colon cancer (4,200), but there were more deaths from lung cancer (6,500). Among women over the age of 75, 5,000 more died of cancer than expected. Declines in lung, prostate, and colon cancer deaths among men and breast and colon cancer among women account for 86% of the recent decline in cancer deaths over the past decade.