Brain and ocular infections can be the worst and fatal consequences of sinonasal infections in immunomodulated or immunocompromised patients. We report a case of a 35-year-old female who received an allogenic hematopoietic stem cell transplantation for acute myeloid leukemia, suffering from maxillo-spheno-ethmoidal rhinosinusitis which was complicated by cavernous sinus thrombosis, orbital cellulitis, optic ischemia and cerebritis.