Case reports have previously been published describing various complications of cytomegalovirus (CMV) and mucormycosis in patients with HIV/AIDS. We describe the first case of CMV vasculitis and mucormycosis coinfection resulting in necrotizing myofascial cellulitis in an extremity in late stage HIV/AIDS. In AIDS patients, CMV reactivates when the CD4 count falls to less than 50 cells/μL (normal, 720-1440 cells/μL). Transient episodes of neutropenia in patients with HIV/AIDS who have low CD 4 cell counts are a predisposing factor for mucormycosis. These predisposing conditions were both present in our patient. Our case raises the question of CMV vasculitis leading to tissue ischemia as a possible contributing factor to the mucormycosis superinfection. © Copyright 2007 Southern Society for Clinical Investigation.