Coccidioidomycosis is caused by a dimorphous fungus, Coccidioides, which consists of two species, C. immitis and C. posadasii. Although these organisms are genetically distinct and do not exchange DNA, they appear identical phenotypically and the disease or immune response to the organisms is also identical. Coccidioides grows as a mycelium in the soil and is mainly found in Southwestern United States, northwestern Mexico, and Argentina. An infection usually results from inhaling the spores of the fungus in an endemic area. Patients with a localized infection and no risk factors for complications often require only a periodic reassessment to demonstrate the resolution of the self-limited process. However, patients with extensive spread of infection or high risk of complications as a result of immunosuppression or other preexisting factors require a variety of treatment strategies such as antifungal therapy, surgical debridement, or both.