In the article titled “Factors Associated with the Incidence and Severity of New-Onset Atrial Fibrillation in Adult Critically Ill Patients” [1], the sentence “However, the AF in non-cardiac surgery patients was also high (10.2%)” in the Discussion should be rephrased to “However, the incidence of AF in all patients (medical or surgical) after excluding those who were not submitted to cardiac surgery was also high (10.2%)” to avoid any misinterpretation.