Although cases of acute rheumatic fever (ARF) have become quite uncommon in North America and Europe, the illness persists as a significant problem globally, remaining a prominent cause of cardiac disease. Rheumatic heart disease is one of the well-recognized noninfectious complications of group A streptococcal pharyngitis. Prompt diagnosis of and treatment for streptococcal pharyngitis prevents ARF. Circumstances that result in missed diagnoses or lack of antibiotic therapy place patients at risk for developing the illness. The signs, symptoms, and laboratory test results included in the diagnostic criteria for ARF, known as the modified Jones criteria, overlap with several other diseases, so it is important to maintain a high index of suspicion for the disease and to include it in the differential diagnosis when appropriate.