Objective: The incidence of invasive fungal infections (IFIs) has increased due to intensive chemotherapy in childhood leukemia. The aim of this study was to evaluate the incidence, risk factors, causative pathogens, and impact on survival of IFIs among pediatric leukemia patients. Materials and Methods: The hospital records of 307 children with acute lymphoblastic leukemia (ALL, n=238), acute myeloid leukemia (AML, n=51), and relapsed leukemia (n=18) between January 2010 and December 2015 were retrospectively evaluated. Results: A total of 1213 febrile neutropenia episodes were recorded and 127 (10.4%) of them were related to an IFI. Of 307 children, 121 (39.4%) developed IFIs. The mean age was significantly older in the IFI group compared to children without IFIs (p<0.001). IFIs were defined as possible, probable, and proven in 73.2%, 11.9%, and 14.9% of the attacks, respectively. Invasive aspergillosis (81.9%) was the most frequent infection, followed by invasive candidiasis (13.4%) and rare fungal diseases (4.8%). The majority of IFI attacks in both ALL and AML occurred during the induction phase. In total, the death rate was 24% and the IFI-related mortality rate was 18%. The mortality rate among children with IFIs was found to be significantly higher than that of children without IFIs (p<0.001). Overall and event-free survival rates at 5 years were also found to be significantly lower in the IFI group (p<0.001). Relapse (odds ratio: 8.49) was the most effective risk factor for mortality, followed by developing an IFI episode (odds ratio: 3.2) and AML (odds ratio: 2.33) according to multivariate regression analysis. Conclusion: Our data showed that IFIs were more common in older children. Although proven and probable IFI episodes were more frequently diagnosed in cases of relapse and AML, children with ALL and AML had similar frequencies of experiencing at least one episode of IFI. Rare fungal diseases were also identified as a major problem. Despite success in treatment, IFIs increased the rate of mortality in children with acute leukemia.