Isolated relapse of myeloid leukemia as a granulocytic sarcoma(GS) following allogeneic bone marrow transplantation(BMT) is very rare manifestation, and usually associated with a poor prognosis. We report a case of isolated intracranial GS in an infant with myelodysplastic syndrome(MDS) following unrelated BMT. A 7 month-old girl was diagnosed with refractory anemia with excess blasts (RAEB). During observation for a couple months several GS developed in the scalp and blast counts in BM increased. Induction chemotherapy resulted in partial remission of BM but GS disappeared. Four months after diagnosis, an unrelated BMT was undertaken. Engraftment was uneventful. On D+160, an intracranial GS of 6.5 cm in size developed. A craniotomy and tumor removal was done. There was no evidence of relapse in BM with complete chimerism. Reinduction chemotherapy using IDA-FLAG resulted in profound neutropenia with pneumonia. She succumbed to respiratory failure despite leukocyte recovery. The optimal management for isolated relapse as GS following BMT should be established.