The evolution of pancreatic cancer incidence in the last three decades in the United States remains unclear. This study was conducted to investigate this problem, using data from the nine registries of the Surveillance, Epidemiology, and End Results (SEER) Program. The incidence data in 1973-2002 were age standardized to the 2000 USA standard population and analyzed by the joinpoint regression. For the nine registries combined, pancreatic cancer incidence in men significantly decreased by 0.62% per year from 1973 to 2002. Incidence in women increased until 1984 and slowly declined thereafter. A rise in incidence, although not statistically significant, has been noted in young and middle-aged adults (<60 years) since 1994. Changes in incidence over time substantially differed among the nine SEER registries compared. Incidence decreased in most age-, sex-, and race-specific groups of the populations covered in the nine registries during the period examined. Conversely, a statistically significant increase in incidence was observed among women in Hawaii and Iowa and among old adults (> or =60 years) in Seattle and Utah. Pancreatic cancer incidence significantly decreased from 1973 to 2002 in men and increased until 1984 and then declined slowly in women in the United States.