The clinical outcomes, including adverse events, in 40 advanced breast cancer patients treated with eribulin were analyzed to confirm the effectiveness and safety of this treatment. The objective response rate (ORR) in patients was 35.0%. The median overall survival and time to treatment failure (TTF) in these patients was 479 and 63 days, respectively. Cases wherein eribulin was used as early-line treatment experienced significantly longer TTF compared to the cases wherein eribulin was used as late-line treatment; however, there was no difference in this value according to the breast cancer subtype. Moreover, subtype analysis revealed no significant difference in adverse events. We observed no difference in the benefit or tolerability of eribulin treatment among different breast cancer subtypes. However, our results suggest that a significant therapeutic effect can be expected when using eribulin as early-line treatment.