Mucormycosis is an aggressive infection that can cause significant disease in immunocompromised patients. Although many patients with rhinocerebral mucormyosis (RCM) undergo similar treatment, pathogen speciation should not be underappreciated; it may be imperative to guide antifungal drug selection, as some mucoraceous fungi may exhibit variable resistance to conventional therapy (Almyroudis et al., 2007; Alvarez et al., 2009). Speciation is also useful to assess the patient’s prognosis. We report a case of a diabetic patient who developed RCM while receiving consolidation chemotherapy for leukaemia. Rhizopus oryzae was identified in tissue biopsies by pan‐fungal PCR and DNA sequencing, which provided the only means to identify the pathogen.