The increased risk of death from cancer in young women attests to its aggressive nature and a greater likelihood of being oestrogen receptor (ER)-negative. Approximately 60% of tumours are ER-positive, however, and thus endocrine therapy is an important consideration in this group. In some countries chemotherapy alone was used for many years until the importance of the additional therapeutic effect of amenorrhea became evident and later, after much scepticism, tamoxifen was shown to be effective in this group of women. Sadly this rather staccato history of treatment has left many questions concerning endocrine therapy in young women unanswered. For example, there have been at least nine studies that show ovarian suppression is equivalent for disease-free and overall survival to chemotherapy, showing equivalent therapeutic advantage. However, the correct design of their studies should have included a third arm of chemotherapy and ovarian ablation and some randomisation to investigate the role of additional tamoxifen. New trials such as SOFT, TEXT and PROMISE will help answer the question of optimal endocrine therapy ± chemotherapy in young women and will also help decide whether aromatase inhibitors are effective in the presence of ovarian suppression. Two further points are important to consider. One is that chemotherapy used alone in very young women with ER-positive disease is detrimental since they do not have chemotherapy-induced amenorrhoea. Secondly, the value of chemotherapy in strongly ER-positive disease is being increasingly questioned.