The number of cases of coccidioidomycosis (incidence) reported to the Arizona Department of Health Services increased from 255 (7.0 per 100,000 population) in 1990 to 623 (14.9 per 100,000 population) in 1995 (P < .001). Four counties in the south central region of the state, which contained 80% of the state's population, had the largest increase and accounted for 95% of all cases in 1995. Cases in persons aged 65 years or older and men were reported more frequently (for both, P < .001). During 1995, 890 patients were discharged from Arizona hospitals with a diagnosis of coccidioidomycosis. Rates of hospitalization were greater among persons aged 55 years or older, men, and African-American (for all three, P < .01). Of the hospitalized patients, 48 died, and 12 (25%) of these patients had a concurrent diagnosis of human immunodeficiency virus infection. These data demonstrate that coccidioidomycosis is a growing health problem in Arizona.