Introduction. The unsatisfactory results of the survival in patients with acute lymphoblastic leukemia (ALL) until 2000 in our center have led us to improve the approach of diagnosis and therapy. Since 2003 in all patients the following have been performed: flow cytometry, conventional genetic diagnosis, FISH (fluorescent in situ hybridization), and molecular biology. Objectives. Our aims were to identify solutions to increase patients’ survival. Patients and method. It is a single-center, retrospective study of 136 patients with ALL treated at 3rd Pediatric Clinic of Timisoara, over a period of 10 years (2003-2012), where survival was assessed. Results. Morphologically, 86% of the patients were L1 type, 13% L2 type and 1% L3 type. Flow citometry revealed that 68% were ALL with B precursors, and 19% with T immunophenotype. Acute leukemia with mixed phenotype (biphenotypic) was identified in 2.3% of patients and 10.7% of the forms were acute leukemia with myeloid markers. In 27.7% of patients, mutations were detected by the RT-PCR method, the most commonly identified was TEL-AML1 (ETV6- RUNX1) accounting for 12.7% of the cases. Relapse-free survival at 5 years for the entire group was 59%, and for the group treated between 2008 and 2012 it was 72%. Conclusion. Our analysis confirms the decisive value of laboratory investigations for the prognosis and improvement of supportive therapy.