Background: Primary laryngomalacia is a congenital weakness of the supraglottis structures which collapsed during inspiration causing upper airway obstruction. This condition can cause changes in gradient of intrathoraxic-abdominal pressure resulting reflux of gastric juice into the upper airway causing laryngopharyngeal reflux (LPR). Purpose: To find out the prevalence of LPR as a comorbid disease of primary laryngomalacia in infant using fiberoptic laryngoscopy examination, to know the characteristics of samples, and the correlation between laryngomalacia with LPR. Methods: This is a cross-sectional study to assess the prevalence of LPR in infants with primary laryngomalacia at Cipto Mangunkusumo Hospital. LPR was diagnosed based on clinical signs from flexible laryngoscopy video records. Result: The prevalence of LPR was 90% in primary laryngomalacia. There were significant differences from three of five clinical findings with LPR, such as arytenoid edema/erythema (p<0,001), ventricular fold edema (p=0,001), and vocal fold edema (p<0,001). Conclusion: Most of the samples with laryngomalacia in this study also have LPR. The presence of LPR could worsen the clinical manifestation and delay the healing of laryngomalacia.