Nasal endoscopy investigation in children aged from 2 till 14 years was made by various endoscopes (flexible — in infants and rigid — with an angle of view of 0° and 30° in older children). At survey the attention was paid to the change of color, hypostasis, a hypertrophy of a mucous cavity of a nose, degree of adenoids, their prelying to choana or prolapse in posterior parts of the nasal cavity, obstruction of pharyngeal mouths of auditory tubes. The conclusion was made that timely diagnostics including nasal endoscopy allows to determine the causes leading to the development of an adenoiditis and to choose the optimum personalized scheme of treatment in each case.