Polysomnography (PSG) is the simultaneous recording of brain signals, muscle activities, respiratory parameters, and cardiovascular signals during sleep, throughout the night. Type I standard polysomnography, which is performed all night in a sleep center under the supervision of a sleep technician, is the gold standard diagnostic method for sleep-disordered breathing. Data recorded overnight is scored manually according to standard scoring rules. First, the sleep phase of the patient is determined on the 30-s epochs, then respiratory events are evaluated on the 2–4-min epochs, arousals are determined, leg movements and cardiac data are evaluated, and scoring is completed. After scoring, a detailed polysomnography report is prepared. The clinician should evaluate the detailed polysomnography report together with the clinical findings of the patient. A diagnosis is made and treatment recommendations are determined taking the clinical presentation of the patient into account and evaluating the findings on polysomnography report including sleep time, sleep architecture, the number, types and durations of respiratory events, how REM and supine position affected the respiratory events, saturation data, minimum oxygen saturation, sleep time when oxygen saturation is <90%, desaturation index, and arousal data. The treatment options are discussed, and decision is made together with the patient. Performing and scoring polysomnography is more difficult in pediatric patients. There are changes in sleep scoring in relation with the brain’s electrical activities that vary according to the age of the child. The main difference in evaluating respiratory events in children is that the two-respiration-time long respiratory events are taken into consideration since respiratory rate is higher in children. The polysomnography report in children should be evaluated by taking age-related sleep times and sleep architecture characteristics into account. The diagnosis should be made according to the diagnostic criteria in children, and treatment decision should be made.