Background Obstructive sleep apnea hypopnea syndrome (OSAHS) is the most common sleep-disordered breathing and is still underdiagnosed.This study was designed to evaluate the value of the STOP-Bang questionnaire (SBQ) in screening OSAHS in sleep-disordered breathing clinics in order to extend it into the general Chinese population.Methods Two hundred and twelve patients undergoing ovight polysomnography (PSG) in the sleep-disordered breathing clinic of Pecking Union Medical College Hospital between May 2011 and January 2012 were prospectively included and were asked to fill in the SBQ.A score of 3 or more of the SBQ indicated a high risk of OSAHS.We analyzed the sensitivities and specificities of SBQ in screening OSAHS.Logistic regression analysis was used to evaluate the probabilities of the severity of OSAHS based upon the apnea hypopnea index (AHI).Results The patients at high risk of OSAHS had higher AHI,higher oxygen desaturation index (ODI),lower pulse oxygen saturation (LSpO2) during sleep time and less sleep time in stage N3.SBQ scores were positively correlated with AHI,ODI and the ratio of SpO2 lower than 90％,and negatively correlated with LSpO2 during sleep.The sensitivities of the SBQ with AHI ≥5/h,AHI ≥15/h,AHI ≥30/h as cut-offs were 94.9％,96.5％,and 97.7％,respectively,and the specificities were 50.0％,28.6％,and 17.9％,respectively.The Logistic regression analysis showed the probability of severe OSAHS increased and the probability of normal subjects decreased with increasing SBQ score.Conclusions The STOP-Bang questionnaire has excellent sensitivity in screening OSAHS patients and can predict the severity of OSAHS.More studies will be required to determine the value of SBQ in the general Chinese population.