Objectives: This retrospective cohort study uses endoscopic assessment of the pharyngeal phase of swallowing in infants with laryngomalacia, to ascertain the impact of infant positioning on airway compromise and fluid dynamics during breastfeeding. The study aims to identify whether modification of infant positioning at the breast may improve the possibility of safe, successful breastfeeding in infants with laryngomalacia and concurrent breastfeeding difficulty. Methods: Twenty-three infants referred for noisy breathing and difficulty feeding were assessed with flexible endoscopic evaluation of swallowing (FEES) during breastfeeding. All had endoscopically confirmed laryngomalacia. During FEES, observations were made of clinical signs of airway compromise as well as endoscopically observable anatomical features and swallowing dynamics during breastfeeding, including tongue base position, view of laryngeal inlet and vocal folds, dynamic supraglottic soft tissue collapse, timing of milk flow into pyriform fossae/hypopharynx relative to sucking, and presence of penetration and/or aspiration. If airway and/or swallowing compromise was present, the infant's initial position at the breast was altered from supine or semi lateral decubitus position to semi-prone, with a description of the clinical and endoscopically observable changes that subsequently occurred. Results: Signs of dynamic airway obstruction and/or compromised airway protection with swallowing were present in 20 of the 23 infants (87%) in their initial supine or semi lateral decubitus position. These 20 infants were repositioned to semi-prone, with improvement and/or resolution of stridor and an improved ability to maintain latch in all infants. Continued endoscopic evaluation following positional change was possible in 16 infants, identifying anterior positioning of the tongue base, reduced dynamic supraglottic tissue collapse, reduced volume of milk flow into pyriform fossae during pauses in sucking and resolution of penetration and aspiration. Conclusion: This study has shown how alteration of breastfeeding position to semi-prone may improve dynamic airway obstruction and reduce aspiration risk in infants with laryngomalacia. [ABSTRACT FROM AUTHOR]