Summary Background Microtubule-targeted agents are one of the most common classes of chemotherapeutic drug for the treatment of breast cancer. Limitations of current microtubule-targeted agents such as primary or secondary resistance of cancer cells and side effects like neuropathy prompted the discovery and introduction of newer more effective drugs. This review aims to provide a summary of the novel halichondrin B analog eribulin mesylate (E7389) and illustrate where it is placed in the treatment arena versus other agents that are approved or are currently in various stages of clinical development. Methods Preclinical and clinical trial (phases I–III) data for eribulin were obtained from scientific journals and meeting abstracts, posters, and oral presentations. The use of current and other emerging microtubule inhibiting agents in breast cancer was also surveyed and briefly reviewed. Results Eribulin mesylate at a dose of 1.4mg/m2 given on days 1 and 8 of a 21-day cycle increased overall survival in patients with metastatic breast cancer (MBC). Neutropenia, fatigue, alopecia, nausea and anemia were common adverse events (AEs) associated with eribulin in clinical studies. A low incidence of peripheral neuropathy was also associated with eribulin in clinical studies (21–26%). Other emerging microtubule targeted agents, such as vinflunine and larotaxel, also reported efficacy in patients with MBC who had received prior chemotherapy, with grade 3/4 neutropenia being the most common AEs for both agents. Conclusions Eribulin mesylate offers clinical activity in advanced breast cancer through improved overall survival, its favorable side-effect profile and convenience of preparation and administration.