Adverse mortality experience of a southwestern American Indian community: overall death rates and underlying causes of death in Pima Indians. As part of an ongoing epidemiologic study, the death rate and causes of death during 1975 through 1984 were determined in Pima Indians who resided in the Gila River Indian Community (GRIC) in 1965 and later. Death certificates were available for 677 of the 681 deaths. In 78% of the deaths, the underlying cause recorded on the death certificate agreed with the cause determined after review of all available relevant records. The age- and sex-adjusted average annual death rate for the GRIC population (1639/100,000) was 1.9 times (95% CI 1.7-2.0) the 1980 rate for the U.S. all races (878/100,000). In Pima males, whose death rate was substantially higher than that of Pima females, the age-adjusted death rate was 2.3 times that in U.S. males, all races. Moreover among males 25-34 years of age, the Pima death rate was 6.6 times that for the U.S. all races. Diseases of the heart and malignant neoplasms caused 59% of U.S. deaths in 1980, but only 19% of GRIC deaths. By contrast, the age- and sex-adjusted mortality rate in the GRIC Pima was 5.9 times the rate of the U.S. all races for accidents, 6.5 times for cirrhosis, 7.4 times for homicide, 4.3 times for suicide, and 11.9 times for diabetes. Tuberculosis and coccidioidomycosis were important causes of death in the Pima, for whom infectious diseases was the tenth leading cause of death. The findings indicate that programs to improve the adverse mortality experience of the GRIC population should emphasize factors related to fatal accidents, alcoholic cirrhosis, homicide, suicide, diabetes mellitus, and infectious diseases. Young Pimas, especially the males, should be the primary focus of such preventive efforts. These findings and recommendations probably apply to many Native American populations. 