Material and Methods: Eighty patients of Abolfazle clinic in Bushehr with abnormal uterine bleeding and simple endometrial hyperplasia enrolled in this study. The patients were randomized in 2 groups: group A included 40 patients who received 10 mg medroxyprogesterone acetate for 10 days in each month during 3 months and group B included 40 patient that received 2.5 mg letrozole for 3 months. Serial transvaginal sonography and estradiol were checked basically and repeated after 3 months of treatment. Main outcome measures were endometrial thickness and estradiol level in serum.

Result: In 2 groups A & B, there were no significant differences in the base variables. The level of estradiol in groups A and B before treatment was similar in the 2 groups. Endometrial thickness in groups A and B was not statistically significant. The difference between these 2 groups from the endometrial thickness reduction viewpoint, is not significant (P value = 0.445). The level of decline estradiol in serum in the groups A&B was significant,

Conclusion: Letrozole is an acceptable drug for treatment of simple endometrial hyperplasia especially in the patients who did not tolerate medroxyprogesterone.