Coccidioidomycosis is a fungal infection contracted through the inhalation of airborne spores, which are most frequently present in desert areas of the southwestern United States and Mexico. Primary immune response to infection is by T(H)1, a subset of helper T cells. Although pulmonary symptoms are most common, hematogenous systemic spread can also occur. Pregnancy is a well-noted risk factor for disseminated Coccidioides infection. The objective of this review is to provide an overview of coccidioidomycosis and to review immunologic and hormonal factors that increase risk of dissemination in pregnancy. Dissemination may occur more frequently in pregnant patients than in nonpregnant women because of shifts in T-cell immunity, changes in cytokine production, and increased hormone levels. There is disagreement regarding the precise incidence of systemic spread in pregnancy, but most sources agree that risk is substantially increased and vigilance must be high in patients with exposures in endemic areas.