What is the current burden of infertility attributable to PCOS at global, regional, and national levels by age and socio-demographic index (SDI) across 21 regions and 204 countries and territories?The burden of infertility attributable to PCOS increased from 6.00 million prevalent cases in 1990 to 12.13 million in 2019 globally and increased sharply in most regions and nations.PCOS is the most common cause of anovulatory infertility, affecting up to 80% of women with anovulation. No comprehensive and detailed epidemiological estimates of infertility attributable to PCOS in reproductive women aged 15-49 years by age and SDI, at the global, regional, and national level, have been reported.An age- and SDI-stratified systematic analysis of the prevalence and years lived with disability (YLD) of infertility attributable to PCOS across 21 regions and 204 countries and territories from 1990 to 2019 has been performed.The prevalence and YLD of female infertility attributable to PCOS in reproductive women aged 15-49 years from 1990 to 2019 were retrieved directly from the Global Burden of Diseases 2019. The number, rates per 100 000 persons, and average annual percentage changes (AAPCs) of prevalence and YLD were estimated at the global, regional, and national levels.Globally, the prevalent cases of infertility attributable to PCOS among women of reproductive age (15-49 years) doubled from 1990 to 2019, with 6.00 million prevalent cases in 1900 and 12.13 million in 2019. The global age-standardized prevalence rates (ASPRs) of infertility attributable to PCOS were 223.50/100 000 persons in 1990 and 308.25/100 000 persons in 2019. At global level, the YLDs of infertility attributable to PCOS increased by 98.0% from 35.20 thousand in 1990 to 69.70 thousand in 2019. The burden of infertility attributable to PCOS in the high SDI region was significantly higher than that in the other four SDI regions. The greatest annual increases in rates of ASPR and age-standardized YLD rate were observed in the middle SDI region (AAPC 1.96 [95% CI 1.87-2.06], 1.94 [1.87-2.00], respectively) and the low-middle SDI region (AAPC 1.96 [1.90-2.03], 1.90 [1.85-1.94], respectively). The regional highest ASPR and the age-standardized YLD rate of infertility were observed in High-income Asia Pacific. The national highest ASPR and the age-standardized YLD rate of infertility were observed in Italy. Positive associations were observed between these burden estimates and the SDI level (all P < 0.001).Although the Global Burden of Diseases 2019 has tried its best to collect all available data, some countries have limited data, which may result in an underestimation of the burden of infertility attributable to PCOS. The diagnostic criteria of PCOS are constantly changing, which may induce bias in infertility attributable to PCOS. No information on the PCOS phenotype is provided in the Global Burden of Diseases 2019, so we cannot estimate the infertility attributable to a specific PCOS phenotype. Detection bias would lead to a higher prevalence of PCOS and infertility attributable to PCOS in developed countries with well-established medical systems and greater willingness of the populace to seek medical attention. Thus, health resource allocation for infertility attributable to PCOS in low-prevalence areas should not be ignored.The global burden of infertility attributable to PCOS increased sharply from 1990 to 2019. Effective health interventions and efficient preventative and managerial strategies should be established to reduce the burden of infertility attributable to PCOS. Weight control is suggested to reduce the burden of infertility attributable to PCOS, especially in the high SDI region.This study was supported by the National Key Research and Development Program of China (grant number, 2022YFC2704100) and the National Natural Science Foundation of China (Nos 82001498 and 82371648). The authors declare no competing interests.N/A.© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.