Tacrolimus is an immunosuppressive drug used to lower the risk of transplant rejection in individuals after solid organ or hematopoietic transplantation. Cases of posterior reversible encephalopathy syndrome (PRES) as a complication of tacrolimus therapy are infrequently documented. The pathogenesis of this phenomenon is not well understood. Here, we report a case of an 18-year-old female with a history of acute myeloid leukemia that developed PRES after undergoing an allogeneic stem cell transplant and subsequent immunosuppressive therapy with tacrolimus