Objective To invesitgate the prevalence of pulmonary thromboembolism （PTE） in hospitalized patients with obstructive sleep apnea-hypopnea syndrome （OSAHS）from January 2004 to December 2008，and analyse its impact on the severity of OSAHS. Methods Demographic and clinical characteristics of 24 OSAHS patients complicated with PTE were analyzed. 30 OSAHS patients without PTE were served as controls. Results PTE was detected in 2.44% （31/1268） of the OSAHS patients. When compared with the OSAHS patients without PTE，the OSAHS patients with PTE had a significantly higher apnea hypopnea index （AHI） [（27.8±11.6）/h vs. （18.2±8.1）/h，P=0.038] and a lower LSpO2 （lowest saturated pulse arterial oxygen level） [（78.4±8.5）% vs. （85.2±7.9）%，P=0.035]. Both groups received continuous positive airway pressure （CPAP） ventilation. Anticoagulation and/or thrombolysis treatment were used in the OSAHS patients with PTE. Conclusions We found a higher prevalence of PTE in patients with OSAHS. Compared with those without PTE，OSAHS patients with PTE have more severe sleep apnea-hypopnea and hypoxemia in sleep. Comprehensive treatments including anticoagulation and CPAP should be used in these patients.