Objective: to evaluate the mid-luteal phase resistant index (RI) and pulsatlity index (PI) of uterine and ovarian arteries with evaluation of endometrial and sub endometrial blood flow in unexplained infertility patients and compare those parameters with fertile controls in order to reveal the possible role of the uterine perfusion in the infertility etiopathogenesis. Methods: in this study, randomized study include 100 participants presented to the outpatient clinic in Kasr El Aini maternity hospital, they were classified into two groups (Group A): 50 participants presented with unexplained infertility either primary or secondary (the case group). (Group B): 50 participants who had no history of infertility and multipara who came for any gynecological procedure (the control group) Primary outcome measures resistant index (RI) and pulsitility index (PI) of both uterine and ovarian arteries with detection of (VI) (FI) & (VFI) of endometrial and subendmetrial areas using (VOCAL) in mid luteal phase after measurement of serum progesterone level in both groups. Results: The uterine artery (RI) is higher in case group (0.86 ± 0.06) (0.85 ± 0.07) than in control group (0.77 ± 0.04), The ovarian artery (RI) is higher in case group (0.66 ± 0.03) (0.65 ± 0.08) than in control group (0.63±0.02). The uterine artery (PI) is higher in case group (2.17 ± 0.22) (2.14 ± 0.16) than in control group (1.80 ± 0.10) (1.80 ± 0.15) and the ovarian artery (PI) is higher in case group (1.97 ± 0.13) (1.97 ± 0.12) than in control group (1.54 ± 0.17) (1.56 ± 0.17) which all statistically significant. As regards endometrial vascularity index (VI), it was higher in control group (0.64 ± 0.05) than in case group (0.51 ± 0.09), Sub endometrial (VI) also was higher in control group (2.34 ± 0.13) than in case group (1.92 ± 0.22), endometrial flow index (FI), it was higher in control group (29.26 ± 1.98) than in case group (24.47 ± 4.19) ,sub endometrial flow index (FI), it was higher in control group (36.29 ± 3.10) than in case group (30.52 ± 2.52) , endometrial vascular flow index (VFI), it was higher in control Group (0.36 ± 0.05) than in case group (0.25 ± 0.04) & subendometrial vascular flow index (VFI), it was higher in control Group (1.13 ± 0.25) than in case group (0.83 ± 0.07) all of that are statistically significant .As regards to serum progesterone level it was higher in control group (12.87 ± 2.47) than in case group (12.66 ± 3.17) which was statistically insignificant. Conclusion: From our study we found that improvement of uterine perfusion could be of value in cases of unexplained infertility.