The aim of this study was to examine improvements or otherwise, in sleep disturbance and breathing difficulties after adenotonsillectomy (AT) for chronic upper airway obstruction in children. In a prospective clinical study and tertiary referral center setting, the study population included consecutive children aged 1.5 through 12 years who underwent AT for chronic upper airway obstruction due to adenotonsillar enlargement, without any history of previous AT. The validated “Symptomatology score” (SS) parameters were used to grade the symptoms before and after AT. The extent of improvement of the symptoms after surgery were estimated by a standardized response mean (SRM). The study included 59 children, 40 of whom were males (68%). Their ages ranged from 1.5 to 12 years with a mean of 3.3 years and 63% were <4 years. The results showed that tonsillar size was correlated significantly with a high preoperative SS ( P ≤ 0.001). The mean preoperative SS for the study population was 7.2, whereas the mean postoperative SS was 1.7. This change was highly significant ( P < 0.001). The symptom domain with the greatest change in mean score was snoring, which improved by 2 points with SRM of 2.2. The changes in total score and in the scores for each symptom domain were highly significant ( P < 0.002). We concluded that adenotonsillectomy is associated with remarkable improvement in breathing difficulties and sleep disturbances in children with obstructive adenotonsillar hypertrophy regardless of the condition whether it is mild or severe.