The management of early breast cancer has evolved rapidly in recent years. Consequently, the range of first-line treatment options for metastatic breast cancer (MBC) is becoming increasingly complicated and therapy depends on a complex interaction of tumor, patient, and physician variables. Arguably one of the most important factors determining choice of first-line chemotherapy is prior adjuvant therapy. We have reviewed data from large, randomized clinical trials to identify the most effective regimens and help clinicians to select first-line treatment based on previous adjuvant therapy. In this review we provide recommendations on the most appropriate first-line therapy according to the type of previous adjuvant therapy. With such a wide array of treatment options available, none is likely to become the gold-standard first-line treatment for MBC. Furthermore, as increasing emphasis is placed on the quality as well as the duration of survival after development of MBC, treatment decisions should take into account tumor characteristics, toxicity, convenience, potential impact on quality of life, and patient preference, in addition to robust efficacy data.