This is a preliminary study investigating the efficacy of aromatase inhibitor anastrozole in treating endometrial hyperplasia in obese postmenopausal women. We administered anastrozole for 12 months to 11 obese postmenopausal women with high operative risk, in order to treat endometrial hyperplasia (four simple, five complex and two atypical). Endometrial thickness in all cases and histology too in the two cases with atypia, revealed atrophical endometrium during treatment and additional mean follow-up of 10.2 months. The safety and tolerance profile was satisfactory. Anastrozole appears to be an interesting new modality for the treatment of endometrial hyperplasia in obese postmenopausal women.