Neonatal hyperbilirubinemia is a prevalent concern in the early stages of life, often necessitating phototherapy. This study aimed to assess the electrolyte changes following phototherapy in neonates admitted to pediatric department In Benha university hospital. Methods: This study was carried out in the NICU of Benha University Hospital and involved the participation of 61 healthy newborns diagnosed with unconjugated hyperbilirubinemia requiring phototherapy. The research included a comprehensive evaluation, comprising detailed maternal, obstetric, and neonatal histories, meticulous clinical examinations, and a diverse range of investigations. These investigations involved complete blood counts, determination of blood group, profiling of bilirubin levels, and the quantification of electrolyte concentrations (sodium, potassium, chloride, calcium, and magnesium). Blood samples were collected both before and after the phototherapy sessions. Results: This study involved a cohort of 61 cases, with 32 being male (52.5%) and 29 female (47.5%). Their ages had a mean ± SD of 5.77 ± 1.94. 41 cases had a Normal Birth weight. The mode of delivery revealed that 44.3% of cases were delivered through Normal Vaginal Delivery (NVD), while 55.7% were delivered through Cesarean Section (CS). Examining gestational age, the majority (62.3%) fell within the 36–39-week range, 26.2% had a gestational age of ≥40 weeks, and the Mean ± SD gestational age was 38.0 ± 1.84 weeks. Of the cases, 68.9% underwent conventional phototherapy, while 31.1% were treated with LED.