Introduction: The efficacy of vitamin D3 for heart failure remains controversial. We conducted a systematic review and meta-analysis to explore the impact of vitamin D3 on heart failure patients. Methods: We searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2018 for randomized controlled trials (RCTs) assessing the effects of vitamin D3 versus placebo on heart failure. This meta-analysis is performed using a random-effect model. The primary outcome is a change in left ventricular ejection fraction (LVEF). Secondary outcomes include 6 minute walking test (6MWT) change, 25-hydroxyvitamin D (25(OH)D) change, brain natriuretic peptide (BNP), hospitalization rate and mortality. Results: Eight RCTs are included in the metaanalysis. Overall, compared with the control group for heart failure, vitamin D3 supplementation results in improvement in LVEF (MD=7.89; 95% CI=7.17 to 8.60; P<0.00001), 6MWT change (MD=11.55; 95% CI=10.94 to 12.16; P<0.00001) and 25(OH)D (MD=47.03; 95% CI=31.68 to 62.38; P<0.00001), but has no significant effect on BNP (MD=-447.02; 95% CI=-1262.67 to 368.62; P=0.28), hospitalization rate (RR=1.64; 95% CI=0.37 to 7.20; P=0.51) and mortality (RR=1.12; 95% CI=0.77 to 1.64; P=0.55). Conclusions: Vitamin D3 supplementation can provide some benefits for heart failure patients.