The superiority of the pediatric protocol for adolescents with acute lymphoblastic leukemia (ALL) has already been demonstrated, however, its efficacy in young adults remains unclear. The ALL202-U protocol was conducted to examine the efficacy and feasibility of a pediatric protocol in adolescents and young adults (AYAs) with BCR-ABL-negative ALL. Patients aged 15-24 years (n=139) were treated with the same protocol used for pediatric B-ALL. The primary objective of this study was to assess the disease-free survival (DFS) rate and its secondary aims were to assess toxicity, the complete remission (CR) rate and the overall survival (OS) rate. The CR rate was 94%. The 5-year DFS and OS rates were 67% (95% confidence interval (CI) 58-75%) and 73% (95% CI 64-80%), respectively. Severe adverse events were observed at a frequency that was similar to or lower than that in children treated with the same protocol. Only insufficient maintenance therapy significantly worsened the DFS (hazard ratio 5.60, P<0.001). These results indicate that this protocol may be a feasible and highly effective treatment for AYA with BCR-ABL-negative ALL.