In recent years increasing evidence proposed that local immune cells at implantation site have largely contributed to embryo implantation. The intrauterine infusion of activated peripheral blood mononuclear cells culture 2 days before embryo transfer can enhance the implantation. One of the methods used to evaluate the endometrial receptivity is by assessing the sub endometrial blood flow. A total of 67 infertile women (30) women receives intrauterine non-invasive insemination of peripheral blood mononuclear cells (PBMC) culture 2 days before embryo transfer representing the PBMC test group, and (37) women without receiving any cell as Non-PBMC group. The cultured PBMC are administered into the uterine cavity of the patients. 2 days later, embryos are transferred into the uterine cavity. Endometrial thickness and sub-endometrial blood flow measurements are taken for all cases on trigger and embryo transfer days. On embryo transfer day there was no significant difference (p = 0.770) in mean endometrial thickness between the PBMC group and Non-PBMC group. There was a significant difference (p< 0.001) in the mean resistive index; the level being lower in the PBMC group. Moreover, there was a significant difference (p< 0.001) in the mean pulsatility index. Regarding all enrolled women, the pregnancy rate of 25.4 %, the rate was higher in the PBMC group in comparison with the Non-PBMC group, 43.3 % versus 10.8 %, respectively and the difference was significant (p = 0.002). The use of PBMC culture can improve sub-endometrial. Endometrial Receptivity, ICSI, Fresh Embryo Transfer, Peripheral