BACKGROUND: Previous meta-analyses suggest that pre-procedural use of statin therapy may reduce atrial fibrillation (AF) following invasive cardiac interventions (coronary artery by-pass grafting and percutaneous coronary intervention). However, the current evidence on the benefit of statins unrelated to invasive cardiac interventions has not been clarified systematically. METHODS: Through a systematic literature search, trials examining the effect of statin therapy on AF were selected. Trials using statins before any percutaneous or surgical cardiac interventions were excluded. RESULTS: The search identified 11 randomized and 16 observational eligible studies, totaling 106,640 patients receiving statin therapy and 129,305 serving as controls. Fourteen studies investigated the effect of statins on new-onset AF, 13 studies investigated the effect of statins on recurrent AF and one in both new-onset and recurrent AF. In the statin versus control group the mean age was 60.7±8.3 versus 68.6±6.2years and females comprised 8.4% versus 10.3%. Statin therapy was associated with significant reduction of AF (Risk ratio (RR): 0.81 [95% confidence interval (CI): 0.80-0.83], p0.05. Assessing exclusively observational studies the risk reduction of new-onset AF was 12% (RR: 0.88 [95%CI: 0.85-0.91], p