Mucormycosis (zygomycosis) is an emerging fungal disease in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. A 30-year-old woman diagnosed with acute myelomonocytic leukemia and needing allo-HSCT presented pulmonary and cerebral infection due to Rhizomucor pusillus. This fungal infection was treated with surgical treatment and posaconazole delayed-release tablets. This strategy allowed reaching high drug levels that could not be obtained with the posaconazole solution.