Background The modified polycystic ovary syndrome health-related quality-of-life questionnaire (MPCOSQ) is a 30-item instrument measuring quality-of-life in English-speaking patients with polycystic ovary syndrome (PCOS). We aimed to: 1) cross-culturally adapt the MPCOSQ into Chinese, and 2) assess the validity and reliability of the Chinese version of the MPCOSQ (Chi-MPCOSQ). Methods The MPCOSQ was translated using the forward-backward method, and its validity and reliability were assessed among 283 Chinese patients with PCOS. Internal consistency reliability and test-retest reliability were assessed by Cronbach's alpha and intra-correlation coefficient (ICC), respectively. Construct validity was tested through exploratory factor analysis and confirmatory factor analysis. Discriminant validity was assessed by Mann-Whitney U test to compare the scores on the Chi-MPCOSQ between 283 women with PCOS and 93 women without PCOS. Results Exploratory factor analysis generated a 7-factor structure of the 30-item version of the Chi-MPCOSQ, which accounted for 77% of the overall variance. The Chi-MPCOSQ had high internal consistency (Cronbach's alpha = 0.88) and good test-retest reliability (ICC = 0.89). Compared to PCOS patients, women without PCOS had consistently lower scores for every dimension of the Chi-MPCOSQ, demonstrating its good discriminant validity. Conclusion The Chi-MPCOSQ is a valid and reliable instrument for measuring quality-of-life among Chinese women with PCOS.