Eustachian tube (ET) dysfunction play an important role in the development, persistence and recurrence of otitis media with effusion (OME) and chronic otitis. Evaluation of the type of obstruction in the cartilaginous portion of ET is important for decision concerning methods of treatment and prognosis of surgical outcome. The aim of this study was to identify characteristics of dynamic function of the pharyngeal orifice of ET in children with OME and chronic otitis by video endoscopy. Transnasal endoscopic examination of the nasopharyngeal opening of ET during swallowing was performed on 21 children – 13 with OME, 8 with chronic otitis. Video recording were made for dynamic slow-motion analysis of ET dilation and closing processes. Most cases of ET dysfunction in children were obstrucive (81%), associated with mucosal oedema and hyperplasia. Dynamic type of dysfunction is caused by the reduced movement of the tensor veli palatini. Dynamic video analysis is useful in the identify type of ET dysfunction in children. Obstructive dysfuntion need diagnostic procedures for chronic infection, nasopharyngeal reflux and alergic diseases.