Purpose: Several studies have reported that the survival after distant metastasis in younger patients with breast cancer was similar to that in elderly patients. Moreover, few studies have observed better survival outcome after distant metastasis in younger patients with breast cancer. Here, we have identified the factors that affect the prognosis after distant metastasis in these patients. Methods: We reviewed 7,157 patients that underwent primary breast cancer surgery between January 2003 and December 2013 at the Samsung Medical Center. Three hundred and thirty two premenopausal patients aged <50 years showed distant metastasis and were included in the analysis. For further analysis, the patients older or younger than 40 years were divided into 2 groups. Results: There were no demographic differences in the patient characteristics such as clinical stage, nuclear grade, lymphovascular invasion, distant metastasis site, distant metastasis free interval (DMFI), except the estrogen receptor (ER) and progesterone receptor (PR) statuses, histopathology, and molecular subtype in both the groups (p-value=0.023, 0.035, 0.016, 0.046, respectively). The median follow-up period was 79.4 months. Next, we did not observe significant difference in the overall survival (OS) between the two groups (Log rank p-value=0.975). However, patients in the luminal A and luminal B group showed better OS than those in human epidermal growth factor receptor-2 (HER-2) positive, and triple-negative breast cancer (TNBC) group (Log-rank p-value<0.001). Furthermore, patients showed worse OS when they developed distant metastases within 36 months post-surgery (Log-rank p-value<0.001). In overall, age did not affect the survival outcome (p-value=0.547); however, the molecular subtype, DMFI, and distant metastasis sites showed significant differences in the patient outcome (p-value<0.001, respectively). Conclusion Our analysis suggests that the molecular subtype, DMFI, and distant metastasis site serve as useful predictors for prognosis in younger breast cancer patients with distant metastasis. However, age in these patients did not correlate well with mortality.