Introduction: SAOS takes the cardiovascular repercussion (RCV) with loss of down nocturnal of the pressure artery (DNPA). Adenotonsilectomy (AT) is the treatment standard gold of SAOS in children, therefore, children with SAOS must have greater after possibility of DNPA normalization adenotonsillectomy. Objectives: to analyze which effective polysomnographic definition better defines SAOS in children. Methods: Children (26), between 8 and 12 years, with snore, apneas and hypertrophy to adenotonsillar had after carried through 24-hour polysomnographic and monitoring of arterial pressure before and AT. Three definitions of SAOS in children (D1: IAH>1; D2: IA>1 or IAH>4; D3: IAH>5) had been applied, separating in carriers of SAOS or Primary Snore. For logistic regression which better definition was calculated correlated SAOS diagnosis, adenotonsillectomy, RCV in the SAOS validity and the improvement after the treatment. Excluded the children with previous diagnosis of cardiac, renal and neurological illness. Results: Ten children had presented loss of the DNPA and in four the DNPA persisted after at exactly. For the D1 definition, it did not have correlation between SAOS and RCV, nor before and nor after AT. For the D3 definition had correlation between SAOS and the RCV before at, but not after. The D2 definition showed significant correlation enters the diagnosis of SAOS, the surgery and the RCV before and after at. Conclusion: The diagnostic criterion of IA>1 and/or IAH>4 is what better defines SAOS in children. Studies involving bigger casuistry with cardiovascular repercussion must be carried through to define the polysomnographic diagnostic criteria of SAOS in children.