Abstract Background The development of new-onset atrial fibrillation in sepsis has been associated with adverse outcomes. Methods A systematic literature search was conducted to retrieve articles that investigated the association of new-onset atrial fibrillation in patients diagnosed with sepsis. The primary outcome of interest was the pooled risk ratio (RR) of in-hospital mortality in patients with new-onset atrial fibrillation and sepsis. Results Six studies included 3100 patients with new-onset atrial fibrillation in sepsis and 36,900 patients without newonset atrial fibrillation in sepsis. The pooled RR for in-hospital mortality was 1.45 (95 % CI 1.32–1.60, p