The role of autologous bone marrow transplantation (ABMT) in childhood ALL after an isolated extramedullary (IE) relapse is controversial. Between December 1984 and November 1995, 52 children underwent ABMT because of an IE relapse. The data were stored in the AIEOP-BMT Registry. Thirty four children were transplanted in 2nd CR; eighteen > 2nd CR. The median duration of 1st CR was 24 (range 3-69) and 18 (range 3-59) months, respectively. The median interval from last CR to ABMT was 6 (range 1-28) and 3 (range 1-81) months, respectively. The 5 year EFS for patients transplanted in 2nd CR was 67.7%, while the 3 year EFS for patients in > 2nd CR was 16.7%. In conclusion, ABMT was an effective treatment in early IE relapse only if performed in 2nd CR.