Coccidioidomycosis is a pulmonary infection caused by the dimorphic fungi Coccidioides immitis and Coccidioidomycosis posadasii. This disease is endemic to the southwestern United States and has a predilection for immunocompromised patients. Diabetes mellitus has been shown to be a strong risk factor for acquiring this infection in these states. Most cases are asymptomatic or present with mild pulmonary symptoms. However, untreated pulmonary mycosis can lead to disseminated infection, most often involving meningitis, osteomyelitis, or skin and soft-tissue infections. When there is arthritis, the knee is the most common site of infection. We present a case of a 23-year-old male with longstanding, uncontrolled Type 1 diabetes mellitus who was found to have pulmonary coccidioidomycosis following diagnosis of coccidioidomycosis osteomyelitis of the knee.