The authors report the case of a 58-year-old female patient with a life-threatening invasive fungal disease caused by a coinfection of Aspergillus and Mucor species that occurred during induction and consolidation chemotherapy for an acute myeloid leukemia. The disease was successfully treated with an aggressive therapeutic approach, which consisted of liposomal amphotericin B in combination with surgical exploration without compromising the treatment of her underlying disease. The case demonstrates the difficulties associated with establishing a diagnosis as well as the need for close observation to identify these infections, which are often misdiagnosed and only suspected late during the course of the disease. Doubts about the reliability of the diagnostic tools lead to uncertainties with regard to the choice of first-line drugs as well the selection of the most appropriate therapeutic strategy in hematologic patients.