We report a fatal case of a rhino-cerebral zygomycosis, caused by Rhizopus arrhizus (oryzae). The patient was suffering from idiopathic thrombopenic purpura, diagnosed 1 year earlier. He was already treated with methylprednisolone 5 months prior to his admission to the hospital for a loss of vision and pain in the left eye as well as left orbital cellulitis. After an initial empirical treatment with broad spectrum antibiotics and voriconazole (infection of unknown origin), the patient was treated with liposomal amphotericin as soon as a positive fungal culture revealed a zygomycete. Unfortunately, the mould was resistant to amphotericin B (MIC: 16 microg ml(-1)) and probably to posaconazole (MIC: 4 microg ml(-1)), which was co-administrated a few days later.