Short binasal prongs can cause skin and mucosal damage in the nostrils of preterm infants. The objective of this study was to investigate the incidence and severity of nasal injuries in preterm infants during the use of short binasal prongs as non-invasive ventilation (NIV) interfaces. A prospective observational study was carried out in the public hospital in a Southern Brazil. The incidence and severity of internal and external nasal injuries were evaluated in 28 preterm infants who required NIV using short binasal prongs for more than 24 hours. In order to identify possible causes of those nasal injuries, the expertise researcher physiotherapist has been carried empirical observations, analyzed the collected data, and correlated them to the literature data. A cause and effect diagram was prepared to present the main causes of the nasal injury occurred in the preterm infants assessed. The incidence of external nasal injuries was 67.86%, and internal ones 71.43%. The external nasal injuries were classified as Stage I (68.42%) and Stage II (31.58%). All the internal injuries had Stage II. The cause and effect diagram was organized into 5 categories containing 17 secondary causes of nasal injuries. There was a high incidence of Stage II-internal nasal injury and Stage I-external nasal injury in preterm infants submitted to NIV using prongs. The injuries genesis can be related to intrinsic characteristics of materials, health care, neonatal conditions, professional competence, and equipment issues.