Breast cancer rarely occurs in young women (<35 years). Several data indicate that diagnosis is associated with a worse prognosis, due to a more aggressive presentation. Although the effect of chemotherapy for premenopausal women is substantial, recent evidence suggested that patients with age <35 years with endocrine responsive tumors had a significant higher risk of recurrence than older premenopausal patients with such biological characteristics. Whereas premenopausal patients with endocrine nonresponsive disease presented similar outcome. Information from different studies of three major researching cooperative groups on breast cancer patients treated with chemotherapy alone, showed a similar interaction between the age and endocrine receptor status. Innovative treatment strategies needed and the combination of ovarian function suppression with endocrine agents (such as tamoxifen) in adjuvant therapy for endocrine receptor positive tumors could be considered. Moreover, more investigation on chemotherapy, its timing, duration, and intensity are required in the adjuvant care for endocrine nonresponsive disease. A strong emotional involvement is required to those patients approaching to adjuvant therapy, which may complicate the phase of treatment decision making. There is an urgent need for tailored clinical trials on young women with breast cancer diagnosis, to allow significant progress on adjuvant treatment of these population.