Annual asthma hospitalization rates were calculated for California's ethnically diverse population from 1983 through 1996. Trends were examined for four race/ethnicity groups: Hispanics, African-Americans, non-Hispanic Caucasians, and Asians/Pacific Islanders. The overall rate decreased by 30% during the time period. African-Americans had the highest rate, more that three times greater than the rate for Caucasians. Among children, the rates for Caucasians decreased by one-third, while rates increased for Hispanics and Asians. The rate for African-American children remained generally constant and was four times higher than the rate for Caucasians. Data from 1996 were assessed for repeat admissions, age and sex differences in rates, costs, and progress toward national goals.