Objectives There is no meta-analysis about the effects of pegfilgrastim on the occurrence of febrile neutropenia (FN) in pediatric/adolescent cancer patients. The study explored the efficacy of prophylactic pegfilgrastim in preventing FN in children/adolescents with cancer. Methods PubMed, Embase, and the Cochrane Library were searched for studies published before April 7, 2020. The primary outcome was the rate of FN. Effect size (ES) and odds ratio (OR) with 95% confidence intervals (CIs) were used to evaluate the outcome. The ES represented the rate of FN, and the STATA 'metaprop' command was used to synthesize the rate. Results Eight studies were included, comprising 167 patients and 550 courses of treatment. There was no difference between pegfilgrastim and filgrastim for the rate of FN in children receiving chemotherapy (OR = 0.68, 95% CI: 0.20-2.23, P = 0.520). In patients receiving pegfilgrastim, the rate of FN was 25.6% (95% CI: 14.9%-36.3%), the rate of grade 4 FN was 38.3% (95% CI: 19.2%-59.5%), the rate of severe neutropenia (SN) was 40.5% (95% CI: 35.1%-46.1%), and the rate of treatment delays due to FN was 4.8% (95% CI: 0.8%-11.3%). Discussion The number of studies that could be included was small; therefore, a specific type of cancer or a specific treatment could be studied. Heterogeneity was high. Conclusion There was no difference between pegfilgrastim and filgrastim for the rate of FN. The use of pegfilgrastim was still associated with rates of FN, grade 4 FN, severe neutropenia, and treatment delays due to FN in pediatric cancer patients.