Background: Even though many studies have examined the possible effect of low-fat diet on breast cancer survival, the relationship remains unclear. Objectives: To summarize the current evidence about the effect of post-diagnostic low-fat diet on recurrence and all-cause mortality of breast cancer. Methods: We conducted a search of Pubmed, Embase, Web of Science, and Cochrane Library and as a result two randomized controlled trials (RCT) and one large multi-center prospective cohort study with 9,966 breast cancer patients were included in this report. Results: Post-diagnostic low-fat diet reduced risk of recurrence of breast cancer by 23% (HR=0.77, 95%CI 0.63 to 0.94, P=0.009) and all cause mortality of breast cancer by 17% (HR=0.83, 95%CI 0.69 to 1.00, P=0.05). Conclusions: This meta-analysis suggested the post-diagnostic low-fat diet can improve breast cancer survival by reducing risk of recurrence. However, more trials of the relationship between low-fat diet and allcause mortality of breast cancer are still needed.