Background: Implementing evidence-based feeding protocols for premature infants is essential as they significantly enhance clinical outcomes such as improved weight gain, height development, and head circumference measurements. These protocols also facilitate a successful transition to oral feeding, ensuring comprehensive care for premature infants. Aim: Evaluate the effect of evidence-based protocol regarding transition to oral feeding on neonatal nurses and preterm infants' outcomes. The design: is quasi-experimental. Setting: The study was conducted in the NICU at Children's Hospital, Mansoura University, Mansoura City, Egypt.  Subject: The current study involved two groups (nurses and preterm infants) as follows: All nurses (53) working in the previously mentioned setting as well as a convenience sample of (40) preterm infants from both genders. Tools of data collection: Tool I: Demographic Characteristics tool, Tool II: it consisted of two parts  Part one: Neonatal nurses' knowledge about transition to oral feeding in preterm infants: Part two: Neonatal nurses' practical knowledge regarding transition to oral feeding in preterm infants: Tool III:  Neonatal nurses' practices regarding transition to oral feeding in preterm infants. Results: Statistically significant differences (P ≤0.001) were observed in the total scores of neonatal nurses' knowledge and practices related to transitioning preterm infants to oral feeding in NICU settings before and after the introduction of an evidence-based protocol. Conclusion: This indicates that the implementation of the protocol led to improved knowledge and practices among the nurses regarding oral feeding in preterm infants.Recommendations: Healthcare professionals in the neonatal intensive care unit should apply safe, evidence-based practices such as skin-to-skin care, non-nutritive nursing, test weight, alternate feeding modalities, and nipple shields to smooth the transition to full oral feeding.