Background. Our aim was to examine the biological and clinical characteristics of Chinese older children and adolescents with acute lymphoblastic leukaemia (ALL) and their outcomes. Procedure. We retrospectively reviewed the treatment and long-term results of 10- to 18-year-old patients with ALL on the Hong Kong paediatric ALL protocol (n=19) and compared with prior literatures. Results. A total of 10 male and 9 female patients were treated; 4 patients' peripheral white cell counts were more than 100x10(9)/L at diagnosis. T-cell lineage was identified in 4 cases and the remaining had B-cell lineage. Ten had abnormal cytogenetic results. Seventh-day post-oral prednisone treatment responses were favorable for 15 patients. On day 33 of treatment, bone marrow results indicated that 2 patients did not achieve remission. Although the rate of complete remission (CR) was 84%, nine patients experienced significant treatment-related side effects and 2 patients died. There were 4 relapses, and the mean time between CR and relapse was 35 months. The mean follow-up time was 88 months. The 7-year overall survival and event-free survival were 89.5% and 72.9%, respectively. Conclusion. Although apparently with frequent serious therapy related complications, older children and adolescents with ALL had satisfactory prognosis if treated with pediatric oriented protocol.