Pelvic inflammatory disease (PID) is a widespread female public problem worldwide. And it could lead to infertility, preterm labor, chronic pelvic pain, and ectopic pregnancy (EP) among reproductive-aged women. This study aimed to assess the global burden and trends as well as the chaning correlation between PID and EP in reproductive-aged women from 1990 to 2019.The data of PID and EP among reproductive-aged women (15 to 49 years old) were extracted from the Global Burden of Disease study 2019. The disease burden was assessed by calculating the case numbers and age-standardized rates (ASR). The changing trends and correlation were evaluated by calculating the estimated annual percentage changes (EAPC) and Pearson's correlation coefficient.In 2019, the ASR of PID prevalence was 53.19 per 100,000 population with a decreasing trend from 1990 (EAPC: - 0.50), while the ASR of EP incidence was 342.44 per 100,000 population with a decreasing trend from 1990 (EAPC: - 1.15). Globally, PID and EP burdens changed with a strong positive correlation (Cor = 0.89) globally from 1990 to 2019. In 2019, Western Sub-Saharan Africa, Australasia, and Central Sub-Saharan Africa had the highest ASR of PID prevalence, and Oceania, Eastern Europe, and Southern Latin America had the highest ASR of EP incidence. Only Western Europe saw significant increasing PID trends, while Eastern Europe and Western Europe saw increasing EP trends. The highest correlations between PID and EP burden were observed in Burkina Faso, Laos, and Bhutan. General negative correlations between the socio-demographic index and the ASR of PID prevalence and the ASR of EP incidence were observed at the national levels.PID and EP continue to be public health burdens with a strong correlation despite slightly decreasing trends detected in ASRs globally. Effective interventions and strategies should be established according to the local situation by policymakers.© 2023. BioMed Central Ltd., part of Springer Nature.