In recent years there has been a significant increase in the number of diseases of the nose and paranasal sinuses (NNPS). According to the observations of S.Z. Piskunov and G.Z. Piskunov (2005), the number of sinusitis cases per 1000 people increased from 4.6 to 12.2 between 2000 and 2004 [54]. During this time interval, the number of patients with MNiONP increased annually by 1.5-2% and reached 52.7%. From 2005 to 2015, patients hospitalized for paranasal sinus diseases accounted for about 2/3 of the total number of patients in specialized hospitals. In Uzbekistan, the incidence of MNIOP is 65-70% and tends to increase. It is connected with significant pollution of the atmosphere with various ecotoxicants, significant decrease of the immune system of the macroorganism, high frequency of mixt-infections leading to the development of purulent-inflammatory process in the paranasal sinuses and development of antibiotic resistance.The monograph covers etiopathogenetic, genetic, clinical and diagnostic aspects of adenoiditis in frequently ill children and approaches to complex treatment.The monograph is intended for otolaryngologists, doctoral students, masters and clinical residents.