Tamoxifen estrogenic action in the uterus induces several uterine diseases, benign and/or malignant ones. The risk of endometrial adenocarcinoma is multiplied by two to three in post-menopausal women. It is mainly linked with the doses and the length of the treatment. However, the global benefit of that drug is not questioned anymore. What matters now though is to find the best way to follow patients on tamoxifen. As a matter of fact, there is no such thing as a consensus that would include specific tests, nor a surveillance protocol in women on tamoxifen. Most teams do not propose any special follow-up. Some patients already show uterine anomalies prior to the beginning of tamoxifen treatment. A yearly gynecologic examination, together with a cervico-vaginal smear, is enough when there are no specific endometrial adenocarcinoma risk factors, nor anomalies detected during the pre-therapeutical evaluation, nor clinical symptomatology. In case of risk factors, or cervical stenosis, or again initial abnormalities though, a yearly transvaginal sonography may be proposed. There is no need for other exploratory examinations if the results are satisfying. In case of symptoms, anomalies in the cervico-vaginal smears, intra-uterine liquid retention with a stenosed cervix, or suspicious endometrial thickness, then an endometrial sampling must be carried out. MRI could be of interest in asymptomatic patients with unclear ultrasonography images. Follow-up must be continued after interruption of tamoxifen. It is important to inform patients about the additional risks of developing an endometrial cancer because of tamoxifen, while still being reassuring. Besides, it is absolutely necessary to recommend them to take quickly medical advice in case of gynecologic symptoms.