Abstract Objective To assess the influence of polycystic ovary syndrome (PCOS) on respiratory events during sleep in nonobese Taiwanese women. Method Overnight polysomnography was recorded in 18 nonobese women with PCOS who had not received treatment (body mass index [BMI] 21.7 ± 0.57, age 29.1 ± 1.43 years) and in 10 age‐ and BMI‐matched women without PCOS (BMI 20.9 ± 0.58, age 31.6 ± 3.87 years). Results The nonobese women with PCOS had a higher total apnea–hypopnea index (AHI) especially during the non‐rapid eye movement stage (AHI NREM ) than the women who did not have PCOS. The women with PCOS had higher serum levels of high‐sensitivity C‐reactive protein (hsCRP) and this was positively correlated with AHI REM . Total testosterone level was positively correlated with AHI NREM , and androstenedione was negatively correlated with AHI NREM . Conclusion PCOS was directly linked to increased obstructive respiratory events during sleep in nonobese women in Taiwan.