Coccidioidomycosis (CM) is a fungal infection endemic in southwestern regions of the United States, northwestern regions of Mexico, and some areas of Brazil and Argentina. Clinical presentation varies depending on the extent of the infection and the immune status of the host. The most common presentation ranges from flu-like symptoms to self-limiting pneumonia. Extrapulmonary presentations are uncommon and may involve the meninges, skin, and bone. Gastrointestinal and peritoneal involvement is extremely rare. Here we report a case of disseminated CM presenting as carcinomatosis peritonei as an AIDS-defining illness in a young male.