This study aimed to determine current practices regarding prophylaxis against infective endocarditis among pediatric cardiologists in the United States 5 years after publication of the most recent American Heart Association (AHA) recommendations. A descriptive, analytical, cross-sectional study was conducted from June 2012 to November 2012 in the format of an anonymous self-administered e-mailed questionnaire among pediatric cardiologists across the United States. The questionnaire inquired about demographic information of cardiologists and their current practices of prescribing preprocedure antibiotic prophylaxis against endocarditis to patients with specific preexisting cardiac conditions. Descriptive analyses were done in percentages. Frequency and exploratory statistical analyses were done by the Chi-square method. Of the 980 cardiologists invited, 221 (23 %) responded to the survey. The findings showed that pediatric cardiologists generally follow the AHA guidelines. The most common cardiac conditions in which antibiotics were administered despite AHA guidelines not requiring prophylaxis were rheumatic heart disease with aortic insufficiency, transposition of the great vessels after the Mustard procedure, bicuspid aortic valve with severe aortic stenosis, cardiac transplantation without valvar disease, and bicuspid aortic valve with severe aortic insufficiency. More experienced pediatric cardiologists were significantly more likely to administer prophylaxis to certain patients than their less experienced peers. Many pediatric cardiologists in the United States continue to administer preprocedure antibiotic prophylaxis against endocarditis even when not recommended to do so per the 2007 AHA guidelines. With certain lesions, highly experienced pediatric cardiologists are more likely to administer prophylaxis than their less experienced counterparts.