The Jones Criteria for guidance in the diagnosis of acute rheumatic fever were first published by T. Duckett Jones, MD, in 1944 and have been revised over the years by the American Heart Association. The current guidelines are an update of these criteria. For the first time, the guidelines are designed to establish the initial attack of acute rheumatic fever. Major manifestations, minor manifestations, and supporting evidence of antecedent group A streptococcal infection are discussed. These updated guidelines expand on the available tools to diagnose streptococcal pharyngitis and clarify the available antibody tests for detecting antecedent group A streptococcal infection. At the present time echocardiography without accompanying auscultatory findings is insufficient to be the sole criterion for valvulitis in acute rheumatic fever. Finally, this article addresses overdiagnosis of rheumatic fever and lists exceptions to the Jones Criteria, including recurrent attacks in individuals with a history of rheumatic fever. (JAMA. 1992;268:2069-2073)