Background: Hormone therapy (H/T) and chemotherapy (C/T) have both improved significantly in the past two decades; however, there were no study addressing head to head comparison between these 2 treatments in estrogen receptor (ER) positive metastatic breast cancer (MBC) patients. Methods: We retrieved the study cohort from the National Taiwan University Hospital cancer registry database, from 2001~2006. All ER(+) and HER2(-) MBC subjects were collected and reviewed. ER(+) was defined as ≥10% positively stained nuclei under immunohistochemical stain. Time to treatment failure (TTF) was defined as the start date of 1^st line treatment to disease progression or the start date of 2^nd line treatment whichever happened first; or the date of death or last follow-up. Overall survival (OS) was defined as the date of diagnosis of MBC to death or last follow-up date. Statistical analysis was performed by Kaplan-Meier method and log-rank test. Results: Excluding 21 pts for lack of sufficient data, 3 pts for OS<3m, and 14 pts received combination of H/T and C/T, a total of 301 pts were analyzed. The choice of treatment modality was under the discretion of attending physicians. H/T was chosen as 1^st treatment in ≥ 60% pts throughout various subgroups. The diseases extent and severity were well balanced between the two groups of patients. We found no significant difference between H/T or C/T in TTF or in OS. Conclusions: There is no significant difference for OS and TTF in ER(+) HER2(-) MBC patients receiving H/T or C/T as their 1^st line treatment. Grant support: DOH 99-TD-C-111-001.