Deaths due to diabetes with acidosis or coma (DAC) in the United States from 1970 through 1978 were analyzed to determine epidemiologic characteristics associated with mortality likely to be due to diabetic ketoacidosis (DKA), a complication of diabetes mellitus considered largely preventable. Annual age-adjusted rates for DAC deaths decreased during the study period, and the secular trend was significant in all regional, race, and sex groups examined. General population-based mortality rates increased linearly with age, were higher in non-Whites than in Whites among persons aged greater than 14, were higher in females, and increased significantly with age in both races and both sexes. By region, rates were lowest in the West. DAC mortality rates specific to estimated diabetic populations decreased annually from 1970 to 1978 in all race and sex groups, and were highest at age greater than or equal to 65, but did not show significant linear increases with age, except in non-Whites. These results indicate declining secular trends, as well as age, race, sex, and regional differences in the risk of such deaths. Further studies are warranted to determine factors contributing to these differences.