Introduction: Invagination cases are cases of pediatric surgical emergencies that are very often encountered, where the most frequent complications are necrosis and perforation. For the digestive system which plays the most role as the immune system is neutrophils. Segmented neutrophils are full capacity active cells containing cytoplasmic granulomas and chromatin–rich hollow cell nuclei. Segmented neutrophils are associated with the body‘s defense against infection and inflammatory processes and are the first cells present when an infection occurs. The purpose of this study is to assess the percentage of segmented neutrophil in invaginated patients at. H. Adam Malik Medan Hospital. Method: This research is a descriptive design study, which was carried out in the Division of Pediatric Surgery, Department of Surgery H. Adam Malik Medan Hospital, by collecting samples from invagination patients’ medical records starting from January 2016 to December 2018 that met the inclusion and exclusion criteria. Data processing is performed using statistical software SPSS programs in the form of tables or diagrams. Results: There were 23 study samples with a mean sample age ≤ 1 year, and the majority were male with 15 patients (65.21%). In this study, the average percentage of segmented neutrophil in patients with invagination in H. Adam Malik Medan Hospital is 62.93%. Segmented neutrophils ≥70% had a lower proportion of 9 patients (39.13%) compared to segmented neutrophils <70% of 14 patients (60.87%). Conclusion: The mean percentage of segmented neutrophil in patients with invagination at the H. Adam Malik Medan Hospital is 62.93%.