With advances in the methods of cancer treatment used in modern medicine, the number of breast cancer survivors has been consistently rising. As the number of women who wish to become pregnant after being diagnosed with breast cancer increases, it is necessary to consider fertility preservation in these patients. However, medical doctors may be unaware of the importance of fertility preservation among cancer patients because most patients do not share their concerns about fertility with their doctors. Considering the time spent choosing and undergoing treatment, an early referral to a reproductive specialist is the best way to prevent a delay in cancer treatment. Since it is not easy to make decisions on matters related to cancer diagnosis and fertility, patients should be provided with enough time for decision-making, and to allow for this, an early referral will provide patients with sufficient time to choose an appropriate method of fertility preservation. The currently available options of fertility preservation for patients with breast cancer include cryopreservation of embryos, oocytes, and ovarian tissue and gonadotropin-releasing hormone agonist treatment before and during chemotherapy. An appropriate method of fertility preservation must be selected through consultations between individual patients and health professionals and analyses of the pros and cons of different options.