TRENDS OF CANCER MORTALITY IN BRAZILIAN STATE CAPITALS, 1980-2004 OBJECTIVE. Cancer mortality rates began to decline in developed countries in the 1990s, but their behavior in developing countries is less well-known. An earlier study on cancer mortality in Brazil showed a declining mortality trend for cancer as a whole. however the quality of data results raised some criticism t. The population of state capitals comprises about a quarter of the total Brazilian population and for these cities mortality data available have a better quality than for the entire country, enabling analyses of trends in cancer rates based on more accurate data. METHODS. Mortality and population data were collected from government databases (SIM/DATASUS and IBGE, respectively). Age-adjusted (world standard) and age-specific mortality rates were calculated for both genders. Linear regression was used to investigate changes in trends. RESULTS. For all cancers as a whole mortality rates declined throughout the study period for both men and women (-4.6% and -10.5%, respectively). For both genders, the cancer that decreased most was stomach cancer Among men, lung cancer death rates presented a slight reduction, while prostate cancer rates increased. Among women, "uterus, site unspecified' presented a downward trend, while lung cancer rates increased. The trend for breast cancer remained stable, and cervix uterus rates showed a slight increase at the end of the period. CONCLUSION. As already seen in developed countries, all cancer mortality rates tended to decline in Brazilian state capitals over the period 1980-2004, a tendency largely due to a decline in stomach cancer death rates for both genders. [Rev Assoc Med Bras 2010; 56(3): 309-12]