Coccidioidomycosis is an increasingly important health problem because of the migration of large numbers of persons to portions of the southwestern United States in which the disease is endemic and because of the increasing numbers of immunosuppressed patients. Most infections due to Coccidioides immitis, although causing significant illness, are self-limited and resolve over a period of weeks to months without specific treatment. It is not known whether antifungal treatment of early infections hastens resolution of the primary illness or prevents complications. Even so, diagnosis of early infections is of value for allaying patient anxiety, lessening the need for further diagnostic studies, decreasing empirical use of antibacterial agents, and facilitating early identification of patients with complications that are more serious. Patients who develop chronic coccidioidal pneumonia or extrapulmonary infection often have complicated courses that require the involvement of various medical, surgical, and radiologic subspecialties for management. Improvement of the ability to control the problem of coccidioidomycosis will require research into the molecular and cellular biology of C. immitis, vaccine development to prevent coccidioidal infection, a better understanding of the soil ecology that supports the fungus in its endemic regions, and discovery of new antifungal drugs. In addition, government agencies, colleges, the military, and employers could improve public health by initiating education programs about the most common manifestations of the disease among persons at risk for infection.