A 6 11/12-year old Negro girl with the adult, Philadelphia chromosome positive form of chronic granulocytic leukemia responded to melphalan for 21 months. Initially, she failed to respond to a low dose of busulfan and was started on melphalan. When her disease became resistant to melphalan, a larger dose of busulfan induced a remission which was maintained with intermittent busulfan for an additional 6 months. She then entered the accelerated phase and died. The prompt and dramatic response to melphalan suggests the importance of further evaluation of this agent.