Objective: The objective of this study was to study the effect of sildenafil citrate and estradiol valerate on endometrial thickness, blood flow, and pregnancy outcomes in women with dysovulatory infertility. Materials and methods: It is a comparative prospective study, including 80 women with primary or secondary dysovulatory infertility. Women with thin endometrium were randomly distributed in two groups. In group I (estradiol group), 40 women were included and given estradiol valerate tablets orally by the step-up method, and in group II (sildenafil plus estradiol group), 40 women were included and given sildenafil citrate tablets orally 25 mg TDS daily in addition to the estradiol valerate tablets as per above the step-up method from day 1 of the cycle until 12th day. Patients were reevaluated by transvaginal sonography (TVS) from day 10th until documentation of ovulation for endometrial thickness and pattern with number and size of graffian follicle. Results: Mean endometrial thickness posttreatment on day 14th was 9.0175 ± 2.58 mm in group I and 9.375 ± 1.989 mm in group II. Only 45% in group I had vascularity up to zone 3, whereas 62.5% patients in group II had zone 3 endometrial vascularity (p value < 0.05). Clinical pregnancy rate in group I and group II was 22.5% and 35%, respectively (p value < 0.05). Conclusion: Both oral estradiol valerate and sildenafil citrate significantly improve endometrial thickness, vascularity, and echogenicity. When compared to estradiol alone (which increases endometrial thickness and echogenicity) but the addition of sildenafil citrate improves endometrial blood flow.