Various transplantation strategies have been designed to improve the poor prognosis of adult (ages 15 to 60 years) acute lymphoblastic leukemia (ALL). The GOELAL02 trial evaluated the impact of early allogeneic bone marrow transplantation (alloBMT) or delayed unpurged autologous stem cell transplantation (ASCT) for patients who had no human leukocyte antigen (HLA)-matched sibling donor or who were older than 50 years. Inclusion criteria included at least one of the following: age older than 35 years; non-T-ALL; leukocytosis greater than 30 x 10(9)/L; t(9;22), t(4;11), or t(1; 19); or failure to achieve complete remission (CR) after one induction course. Among 198 patients, the median age was 33 years. The CR rate was 80% with vincristine, idarubicine, L-asparaginase, and randomized intravenous injection or oral steroids (P = nonsignificant [ns]). AlloBMT was performed after 2 consolidation courses while ASCT was delayed after 1 additional reinduction. Intensified conditioning regimen before transplantation included etoposide, cyclophosphamide, and total body irradiation (TBI). Median follow-up was 5.1 years. The median overall survival (OS) was 29 months, with a 6-year OS of 41%. On an intent-to-treat analysis for patients younger than 50 years, alloBMT significantly improved the 6-year OS (75% versus 40% after ASCT; P = .0027). Randomized interferon-alpha maintenance had no effect on relapse or survival after ASCT. In conclusion, the outcome of adult ALL is better after early alloBMT than after delayed ASCT.