Objective To assess the efficacy of ovulation induction and intrauterine insemination (IUI) in couples with diminished ovarian reserve (DOR). Methods Women aged 20-39 years and men younger than 50 years were included. Four "ovarian reserve groups" were created according to anti-Mullerian hormone (AMH) and the partner's age. Gestational sac finding on ultrasound examination was the primary outcome measure. Results The study was carried out on a total of 770 cycles of 362 women in an infertility cohort that consisted of 75 women with DOR treated by 153 cycles and 287 women without DOR treated by 617 cycles. The pregnancy rate was similar in the four ovarian reserve groups in terms of first, second, third plus fourth, and total attempts of IUI cycles. Moreover, the pregnancy rate, miscarriage rate, and multiple pregnancy rate were similar. We found no difference in the cumulative pregnancy rate among the groups after four IUI cycles. Multivariate logistic regression analysis of the entire cohort revealed that infertility duration, post-wash sperm count, and follicle number greater than 11 mm on the day of human chorionic gonadotropin trigger were independent predictors of pregnancy (P < 0.001). Neither age nor AMH predicted pregnancy after ovulation stimulation and IUI. Conclusions Ovulation stimulation and IUI are equally effective in women with DOR and in women with normal ovarian reserve in terms of pregnancy rate, multiple pregnancy rate, and miscarriage rate per IUI cycle or cumulative pregnancy rate after four cycles of IUI.