Background: This paper summarizes current knowledge about clinically important aspects of gynecological care in female breast cancer patients. Despite the overall positive acceptance of oral contraceptives and hormone replacement drugs, hormone therapy may raise fears of developing breast cancer. Specifics of gynecological care of fertile patients are discussed as these patients face ovarian failure when undergoing oncological treatment of breast cancer. Tamoxifen is used in adjuvant therapy of breast cancer, in metastatic breast cancer or as prophylaxis of breast cancer in high-risk patients. Aim: We aim to study the influence of hormonal treatment on breast cancer development in women with and without congenital predisposition. The main risk factors for developing breast cancer are family history, increased density of breast tissue, atypical hyperplasia of the breast and previous radiotherapy to the chest area. All these factors increase the relative risk of cancer more than four times. Contraceptives and hormone replacement therapy show generally less than two-fold or no increase at all (RR 0.96–1.6). We concentrate with safety of hormonal therapy in breast cancer patients after they finish breast cancer treatment in pre- and postmenopausal period. We discuss fertility-sparing methods for preservation of ovarian function due to oncological treatment. Those methods are cryopreservation of embryos, oocytes in metaphase II and ovarian tissue. Simultaneous administration of GnRH agonists may protect ovarian function before gonadotoxic chemotherapy. We describe in detail the effects of tamoxifen on gynecological organs in both pre- and postmenopausal women in relation to the potential risk of developing secondary malignancy. In premenopausal women, tamoxifen has no increased risk of cancer of the uterine body. In postmenopausal patients, the risk after five years of tamoxifen is increased 2–3 times. Transvaginal sonography is not the screening tool for detection of the pathology in the uterine cavity during tamoxifen therapy, and so we only recommend looking for symptoms. Hysteroscopy is the golden standard for the examination of the uterine cavity in symptomatic postmenopausal patients using tamoxifen. Conclusion: This paper summarizes the current knowledge in areas where oncological and gynecological cares for breast cancer patients mingle. It should lead to greater understanding and deepening cooperation between clinical oncologists and oncogynecologists for the benefit of our patients.