Background: The most frequent side effects of chemotherapy are infections, which have substantial morbidity and mortality rates in immunocompromised patients. Aim: Toscreen the prevalence of resistance between antibiotics administered to infected patients in hematological malignancy wards. Subjects and Methods: A retrospective cross-sectional study of pediatric oncology patients was conducted from January 2021 to June 2022 at Basra children hospital. The study included 500 patients with hematological malignancies.  Results: This study involved 57.8% male and 42.2% female patients. Leukemia was the most common diagnosis 59% while other solid tumors was 41%. Febrile neutropenia was only 5.8%, bacterial infection was predominant at 49.8% while the fungal infection was 9.4%, and 4.8% suspected viral infection. We found that the high percentage of antibiotics used were Cephalosporin (41.4%)  and the lower percentage of antibiotics were Quinolone 0.4%.  Conclusion: The most frequent form of infection was a bacterial infection, and the most frequently prescribed antibiotic for oncology patients was cephalosporin. The chest represented the most severely infected place.