Mucormycosis is a rare, devastating, opportunistic fungal infection, which occurs principally in some particular conditions, specially in non-controlled diabetic patients, notably during keratoacidosis. We report two cases in 62 and 72 year-old diabetic women. In both cases, histologic examination of endobronchial biopsies showed tissue invasion by hyphae with characteristic morphology leading to the diagnosis of pulmonary zygomycosis. This difficult diagnosis must be evoked in diabetic patients with non-responsive lung infections in order to apply early aggressive therapy.