Background: Intensive chemotherapy is required to achieve cure in pediatric oncology patients who are at increased risk for serious infections while neutropenic. Administration of Granulocyte Colony-Stimulating factor (G-CSF) may reduce the severity of neutropenia. This study assessed the efficacy of adjunctive G-CSF in the treatment of established neutropenia by evaluating clinical outcomes. Methods: Prospective study conducted at the Pediatric Oncology Department, South Egypt Cancer Institute (SECI), Assiut University. Pediatric patients with solid tumors who developed neutropenia after receiving myelosuppressive chemotherapy between February 2018 and February 2020 were included in the analysis. The clinical efficacy of adjunctive G-CSF was evaluated by assessing the duration of neutropenia, duration to absolute neutrophilic count (ANC) recovery, duration of fever, the duration of hospital stay and infection related mortality. Results: Thirty seven patient experienced 50 episodes of neutropenia with de novo solid tumors were analyzed. The median age was 6 years with 60% of episodes occurred in males. Neuroblastoma was the most common underlying malignancy (44%). The majority of episodes had low risk criteria (64%). The mean durations of neutropenia, absolute neutrophil count (ANC) recovery, fever resolution and hospitalization after receiving G-CSF were (6.79±3.80, 15.47±2.85, 4.21±1.73, 7.82± 3.82 days) respectively. Recovery from neutropenia reported in 98% while infection related mortality was 2%. All factors were significantly affecting the pattern of recovery expect gender and disease status. Conclusion: This study suggested that the use of adjunctive G-CSF in established febrile neutropenia may confer clinical benefits among pediatric patients with solid tumors.