We evaluated the efficacy and safety of the conditioning regimen that consisted of TBI and melphalan (L-PAM), followed by hematopoietic SCT (HSCT) in 23 children with advanced hematological malignancies. The median age at HSCT was 9 (range, 2-15) years. The underlying diseases were ALL in 16 patients (5 in CR2, 3 in CR3, 6 in relapse (RP) and 2 in induction failure (IF)), AML in 4 patients (3 in RP and 1 in IF) and non-Hodgkin's lymphoma in 3 patients (1 in CR3, 1 in CR4 and 1 in RP). The stem cell sources were BM for 19 patients and cord blood for 4 patients. All patients received the conditioning regimen that consisted of TBI 12 or 13.2 Gy and L-PAM 210 mg/m(2). In all, 22 patients engrafted on the median of day 16 (range, 10-23). The regimen was well tolerated and common regimen-related toxicities (RRTs) included grade II stomatitis and grade I hepatic toxicity. The cumulative incidences of RP and TRM were 47.6 and 21.5%, respectively. At a median follow-up of 24.4 months, the probability of disease-free survival was 41.0%. The regimen may provide sufficient anti-leukemic effect without increased RRT for advanced pediatric hematological malignancies.