This article reviews and analyzes the recently updated guidelines for the prevention of infective endocarditis (IE) through antibiotic prophylaxis established by the American Heart Association (AHA). Various articles studying methods of preventing IE were reviewed, primarily the AHA's revised guidelines published in April 2007. Lists of reference articles were examined to cross reference relevant information regarding antibiotic prophylaxis for the prevention of IE. A major influence for revisions to the guidelines is that studies show a very small fraction of IE cases are preventable with prophylaxis with antibiotic therapy prior to dental procedures. IE is more likely to result from daily activities, such as brushing and flossing teeth, than from bacteremia caused by dental procedures. Patients with underlying cardiac conditions, who are associated with the most detrimental outcome if IE develops, should receive prophylaxis prior to dental procedures. Maintenance of oral health is more effective in reducing the risk of IE than prophylactic antibiotics for dental procedures. An increased lifetime risk of developing IE alone is not a basis for prophylaxis, especially considering that adverse events stemming from antibiotic use exceed the benefit of antibiotic prophylaxis.