ObjectiveTo assess efficacy (progression-free survival (PFS) and overall survival (OS)) and safety of eribulin in real clinical practice. MethodsObservational and retrospective study. Patients with metastatic breast cancer (mBC) treated with eribulin between 01/04/2014 and 31/10/2020 were included. Age, sex, ECOG performance status, HER-2, hormone receptor status, previous regimens for metastatic disease, previous ratio/hormone/surgical therapy, duration of treatment, toxicity and time to progression or death, were collected. Progression was evaluated by RECISTv1.1 criteria and toxicity by CTCAE.5.0 criteria. Statistical analysis was conducted by Log-Rank's test and Cox's Regression. Results38 patients were included, median age 57,6 years (±11,85), ECOG PS ≥ 2 (84,2%), negative HER2 overexpression (86,8%), hormone receptors expression (84,2%). All patients had already failed 2 chemotherapy regimens. Median duration was 4,35 months (IQR:2,44–6) and median cycles was 6 (IQR:4–8). Delays or reductions were 79% and 60,5%, respectively. Treatment was generally well tolerated, with 15.8% grade 3 and 10.5% grade 4 toxicities. 32 patients deceased, median OS 12,4 months (8,3-16,5). 37 had progressed, median PFS 6 moths (4,85-7,16). Log-Rank's test showed statistically significant difference in OS in patients with previous hormone therapy confirmed in Cox's regression [median 13,8 months (9.9–17.6); HR = 0,34 CI95%(0,12-0,98); p = 0,045 vs 6,5 months (6,1-6,9)]. ECOG PS > 2 showed better PFS in Log-Rank's Test and Cox's Regression [6,5 months (3,65-9,34); HR:0,35 CI95%(0,16-0,75); p = 0.038 vs 3,73 (0,09-7,38)]. ConclusionsEfficacy of eribulin in our real practice is similar to data from clinical essays observing statistically significant more OS in patients with previous hormone therapy and more PFS in ECOG's PS >2 subgroup and less incidence of grade 3/4-toxicity.