Introduction and objectives: Children up to 2 years old are at high risk of respiratory infections and nasal irrigation is often prescribed. Yet, to date there is no sufficient knowledge about its immediate effects on the nasopharynx and middle ear. Therefore, this study aimed to analyze the effect of a rhino-pharyngeal clearance intervention protocol on nasal obstruction and middle ear condition in children under 3 years of age with URTI. Materials and methods: Randomized controlled trial in a day-care centre of Porto, including 44 children randomized to Intervention Group (IG) and Control Group (CG). Nasal auscultation and tympanometry were performed at baseline (M0) as well as after the intervention (M1), which consisted of nasal irrigation (NaCl .9%) followed by a forced nasal inspiration in the IG, and after 30 min of normal activities, in the CG. Results: In M1 there was a lower frequency of children classified as having an obstructed nasal sound in the IG when compared to the CG (IG = 33.3%; CG = 68.4%; p = 0.042). We also observed an improvement of mean peak pressure (PP) in the IG (Left ear: M0 = −124daPa; M1 = −92daPa; p = 0.022. Right ear: M0 = −102daPa; M1 = −77daPa; p = 0.021), which was not observed in the CG (Left ear: M0 = −105daPa; M1 = −115daPa; p = 0.485. Right ear: M0 = −105daPa; M1 = −131daPa; p = 0.105). There were no significant results concerning the compliance of the tympanic membrane. Conclusions: The rhino-pharyngeal clearance improved the nasal obstruction and PP of the middle ear of children under 3 years of age with URTI. 30 min de actividades normales en CG. Resultados: En M1 hubo una menor frecuencia de niños clasificados como con un sonido nasal obstruido en IG en comparación con CG (IG = 33,3%; CG = 68,4%; p = 0,042). También se observó una mejora de la presión máxima media (PP) en IG (oído izquierdo: M0 = −124 daPa; M1 = −92 daPa; p = 0,022; oído derecho: M0 = −102 daPa; M1 = −77 daPa; p = 0,021), que no se observó en CG (oído izquierdo: M0 = −105 daPa; M1 = −115 daPa; p = 0,485; oído derecho: M0 = −105 daPa; M1 = −131 daPa; p = 0,105). No hubo resultados significativos con respecto al cumplimiento de la membrana timpánica. Conclusiones: La limpieza nasal mejoró la obstrucción y la PP del oído medio de niños menores de 3 a˜nos con IRS.