Background: Relapse in leukemic patients is considered as a major cause of treatment failure and a decrease in patient survival rate. This study was conducted to determine the survival rate of patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) based on their relapse status.

Materials and Methods: This retrospective cohort study was performed on a total of 243 cases of leukemia aged less than 15 years in Shiraz Shahid Faghihi hospital. Data were analyzed using Kaplan-Meier method, log-rank test and Cox regression model.

Results: The 1- and 5-year survival rates for patients without relapsed leukemia were 96.9 and 76.9% and for relapsed leukemia were 82.4 and 28.6%, respectively. Therefore, there was a significant relationship between the relapse occurrence and survival rate among the patients (P=0.001).

Conclusion: The relapse occurrence is one of the main effective factors in survival rate of leukemic patients a five-year survival rate in the patients is less than 30 percent in this center.