Language barriers likely impair patients' ability to receive quality health care, but the link between limited English proficiency (LEP) and patient safety has not been extensively researched. This study examined voluntary reports of adverse events reported at six hospitals and found that adverse events were more common in patients with LEP. Events in patients with LEP were frequently attributable to communication problems and were more likely to result in patient harm. Though the study only examined voluntarily reported incidents, it adds to prior research identifying LEP as a potential contributor to adverse events.