From July 1987 to July 1991, 12 children underwent AMBT following high-dose cytarabine (HD Ara-C) plus 14.4 Gy hyperfractionated total body irradiation (hyfr-TBI) for early isolated extramedullary relapse of ALL, while in first BM remission. No patient received intrathecal prophylaxis following AMBT. One patient died on day +5 due to sepsis and three patients, two of them transplanted in second and third CNS relapse, respectively, died from BM relapse occurring 1.5, 4 and 5 months after AMBT. Eight of the 12 survive disease-free with a median follow-up of 24 months (range 14-62 months). The toxicity of HD Ara-C plus hyfr-TBI was acceptable and well controlled with supportive therapy. These results suggest that ABMT following HD Ara-C plus hyfr-TBI may eradicate leukemia from extramedullary sites of ALL relapse.