Malpractice litigation is a major concern when medical errors result in adverse patient outcomes. Fear of malpractice has been associated with excessive health care use through defensive medicine, whereby additional testing or referrals are made to protect physicians from malpractice accusations. Although fear of lawsuits and its implications for decision-making have been well studied, few investigators have examined clinicians' concern regarding causing patient harm, which might be a stronger impetus for excessive testing. This cross-sectional study investigated emergency department (ED) clinicians' concerns about medical errors resulting in either patient harm or malpractice litigation.