Abstract: An ovulation disorders cause 30 to 40 percent of infertility cases. There are several regimens to induce ovulation. Clomiphene Citrate (CC) has been the front-line therapy for ovulation induction, but failure to respond to CC occurs in up to 20% of cases, which may then require the use of other drugs for ovulation induction. The objective of this study is to compare the two drug regimens (Clomiphene Citrate, Tamoxifen and vitE versus estrogen, Letrozole and Tamoxifen) in infertile women with anovulatory cycles. This study is a double blind control trial which was done on 90 infertile women that referred to Dr.Rasekh clinic. Patients were divided into 2 groups blindly. Group A took Clomiphene Citrate, Tamoxifen and vitamin E. Group B took Letrozole, Tamoxifen and Estrogen. Efficacy of each regimen was compared with analyzing endometrial quality and thickening, follicular size pregnancy rate and incidence of OHSS. Results of this study demonstrate that mean of endometrial thickness is more in group B (10.020 vs. 7.360). Endometrial thickness has significant difference between group A and B (p-value<0.001). Mean of follicular size in group A is more than group B (15.630 vs. 14.264). Frequency of OHSS in group B is more than group A (6.7% vs. 0%) (p-value). 0.05) Odds ratio shows that frequency of pregnancy in group B is 9.5 fold more than group A. Comparing the frequency of pregnancy in two groups has significant difference, which shows the efficacy of group B is more than group A regimen.