Objective The purpose of this systematic review and meta-analysis was to evaluate the effectiveness of mindfulness-based stress reduction (MBSR) in breast cancer patients. Methods A systematic search of Cochrane Library, Cochrane Central Register of Controlled Trials, PsycINFO database, Web of science, Medline, EMBASE, CNKI, and CBM database was carried out from February to May 2018, with no language restrictions. Trials examining the effects of MBSR versus control group on symptom variables and health-related quality of life were included. Data concerning studies, patient characteristics, and outcomes were extracted. Methodological quality of each included randomized controlled trials were assessed individually by two reviewers independently using criteria recommended in the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0. Meanwhile, Newcastle-Ottawa Quality Assessment Scale (NOS) was used to evaluate methodological quality of non-randomized studies. Results In all, 14 studies involving 1505 participants were included. Due to the effect of MBSR, statistically significant results were found on physiological function (SMD = 0.28, 95% CI [0.07, 0.049], P = 0.008), cognitive function (SMD = 1.48, 95% CI [0.34, 2.61], P = 0.01), fatigue (SMD = − 0.66, 95% CI [− 1.11, − 0.20], P = 0.004), emotional wellbeing (SMD = 1.01, 95% CI [0.35, 1.67], P = 0.003), anxiety (SMD = − 0.54, 95% CI [− 1.01, − 0.07], P = 0.02), depression (SMD = − 0.61, 95% CI [− 1.11, − 0.11], P = 0.02), stress (SMD = − 0.48, 95% CI [− 0.81, − 0.15], P = 0.004), distress (SMD = − 0.56, 95% CI [− 0.85, − 0.26], P = 0.0002) and mindfulness (SMD = 0.94, 95% CI [0.10, 1.79], P = 0.03). Although the effects on pain, sleep quality, and global QoL were in the expected direction, they were not statistically significant (P > 0.05) based on insufficient evidence. Conclusions MBSR is worthy of being recommended to breast cancer patients as a complementary treatment or adjunctive therapy.