The patient with group A beta-hemolytic streptococcal infection and articular disease who does not fulfill the modified Jones criteria for a diagnosis of acute rheumatic fever(ARF) have been classified as poststreptococcal reactive arthritis/arthralgia. A 10-year-old girl had presented with fever and arthralgia. She had pain in her left knee for 7 days but no swelling. A throat culture showed no growth but antistreptolysin O titer and C-reactive protein were elevated. A clinical follow up one month later showed neither arthralia nor sequelae as acute rheumatic fever. Poststreptococcal reactive arthritis/arthralgia seems to be part of the disease spectrum of ARF and to prevent subsequent development of ARF and carditis in these patient, it is recommended that antistreptococcal prophylaxis should be administered for 1 year and then could be discontinued if there is no evidence of cardiac involvement.