Oral anticoagulants (OACs) are indicated for treatment and prevention of thromboembolic diseases. Supplemental patient education (education) has been proposed to improve outcomes, and this systematic review assesses the effect of education on mortality, thromboembolic events (TEEs) including venous thromboembolism (VTE), and bleeding in patients taking OACs. Randomized controlled trials were included, and 2 authors independently screened articles and assessed risk of bias. In 9 trials (controls, n = 720; intervention group patients, n = 646), 4 assessed critical outcomes of mortality, TEEs (VTE, stroke, and systemic embolism), and bleeding to estimate absolute risk ratios. When comparing education with usual care, in 1000 patients, there may be 12 fewer deaths (95% confidence interval [CI], 19 fewer to 154 more) and 16 fewer bleeding events (95% CI, 34 fewer to 135 more), but this evidence is uncertain; the evidence also suggests 6 fewer VTEs (95% CI, 10 fewer to 16 more) and 8 fewer TEEs (95% CI, 16 fewer to 18 more). The mean difference in time in therapeutic range may be 2.4% higher in the education group compared with usual care (95% CI, 2.79% lower to 7.58% higher). We also found very low certainty of evidence for a large increase in knowledge scores (standardized mean difference, 0.84 standard deviation units higher; 95% CI, 0.51-1.16). Overall, the certainty of evidence was low to very low because of serious risk of bias and serious imprecision. Additional sufficiently powered trials or different approaches to education are required to better assess supplemental education effects on outcomes in patients taking OACs.