Background: Infertility is a serious health issue affecting approximately 15% of couples worldwide. Infertility may bring about unhappy married lives, divorces, and high levels of psychiatric morbidity.Despite the fact that it is a major concern in Ethiopia, scientific data is insufficient to identify significant infertility factors. Objective:-To identify determinants of infertility among married women in Bahir Dar city, North Western Ethiopia 2021. Methods: - An institution-based unmatched case–control study was conducted among married women attending health facilities in Bahir Dar for infertility diagnosis and treatment from October 1, 2021, to November 15, 2021. Study participants were chosen using a systematic random sampling technique.Data were collected from 173 cases and 346 controls using an interviewer-administered structured questionnaire and document review, which was then entered into Epi Info version 3.1, exported to Excel, and analyzed using SPSS version. Variables with P-value ≤0.25 in the simple binary analysis were included in the multiple logistic regression models. Backward stepwise LR method, Odds ratio with 95% confidence interval and the level of statistical significance set at p<0.05 wasused to identify the determinants of infertility. Results:- the determinants of women’s infertility were age of women>30 (AOR = 1.697, 95% CI: 1.118-2.576), Abortion history (AOR = 2.246; 95% CI: 1.262-3.998), irregular patterns of menstruation flow (AOR = 2.310, 95% CI=1.447-3.687), hormonal disorder(AOR = 8.625, 95% CI=3.652-20.366), and history of STI (AOR = 3.638; 95% CI: 1.946-6.801) were significantly associated with women’s infertility. Conclusion:Age of women, history of abortion, irregular patterns of menstrual flow, history of STI, endocrine disease, and stress were independent determinants of infertility in women. As a result, couples should receive health education on not delaying parenthood, STI, Hormonal disorders, and abortion. Key words: - married women, infertility, determinant