Most of the gastric outlet obstruction symptoms like vomiting and abdominal distension were caused by congenital anatomical abnormality in a neonate. Abnormal structures associated with congenital gastric outlet obstruction have been categorized by its site and extent of obstruction. We report one case of persisting vomiting in a premature infant caused by serosal fibrous band in gastric outlet lesion, excluded from the category of congenital gastric outlet obstruction.