Hyperleukocytosis is defined as a white blood cell (WBC) count of ≥ 100,000/µL. Leukostasis refers to symptomatic hyperleukocytosis and is considered a medical emergency. In pediatric practice, hyperleukocytosis is most commonly described in leukemia and other myeloproliferative disorder, but other etiologies, such as infection, are less commonly mentioned. In this case report, a one-day-old, preterm, male baby (26 weeks of gestation) was referred for preterm care. A sepsis-induced leukemoid reaction hyperleukocytosis diagnosis was presumed, and he was successfully treated with an empirical antibiotic with a gradual improvement in WBC counts.