Objective: to compare the efficacy of letrozole and clomiphene citrate in terms of pregnancy achievement and in anovulatory infertile women. Study Design: A randomized controlled trial. Place and Duration: study conducted at the department of obstetrics and gynaecology DG Khan Teaching Hospital. DG Khan from March 2017 to March 2018. Methodology: Two hundred and ten patients were included in this study. The patients were equally divided into two Groups as Group A and Group B by random number method. Study was started after permission from hospital ethical committee. Study variables were age and duration of infertility. SPSS version 24 was used to analyze data. T test and chi square test were applied and p≤0.05 was taken as significant. Results: the mean age and duration of infertility of Group B was 25.66±3.39 years and 3.72±2.01 years, respectively. There were 73.3% patients between 18-30 years and 26.7% in 31-40 years of age. There were 79% patients had <5 years of duration of infertility and 21% had >5 years of duration of infertility. The difference was statistically significant (p=0.000) for age. The efficacy of Group A and B was observed as 16.2% and 45.7%, respectively. The difference was statistically significant, (p=0.000). Conclusion: use of Letrzole is safe and more effective for achieving pregnancy in anovulatory infertile women as compared to clomiphene citrate. Keywords: Letrozole, Clomiphene Citrate, Ovulation, pregnancy rate, Infertility