Coccidioidomycosis inspired the interest of only a few investigators in the United States prior to World War II. Valley fever, desert rhematism, or San Joaquin fever -- as it was commonly known -- appeared to be of local and limited concern. During the war, however, many military bases were established in the semi-arid endemic regions of the Southwest and almost overnight the disease became a major medical problem confronting the Armed Forces. Thousands of personnel stationed in the endemic areas developed disabling and occasionally fatal cases of coccidioidomycosis. Since that time, skin test surveys have shown that millions of people in this country have been infected by Coccidioides immitis and that thousands of new infections occur each year. Publication of these proceedings makes the wealth of material presented on the epidemiology, ecology, immunology, pathology, diagnosis, and treatment of one of man's most important mycotic diseases available to investigators everywhere.