Aim: Subclinical valvar insufficiency, or valvitis, has recently been identified using Doppler echocardiography in cases of acute rheumatic fever with isolated arthritis or chorea. The prognosis of such patients with acute rheumatic fever and subclinical valvitis is critical when determining the duration of antibiotic prophylaxis. We aimed, therefore, prospectively to investigate the association of silent valvitis in patients having rheumatic fever in the absence of clinical evidence of cardiac involvement, and to evaluate its prognosis. Methods and Results: Between November 1998 and September 1999, we identified 26 consecutive patients with silent valvitis in presence of rheumatic fever but in the absence of clinical signs of carditis. The patients, eight female and 18 male, were aged from 6 to 16 years, with a mean of 9.9± 2.7 years. Major findings were arthritis in 16, chorea in 7, and arthritis and erythema marginatum in 1 patient. Two cases had arthralgia with equivocal arthritic signs and Doppler echocardiographic findings of pathologic mitral regurgitation. Silent pathologic mitral regurgitation was found in 12 cases, and aortic regurgitation in 2 cases. All patients with arthritic findings were treated with acetylsalicylic acid with one exception, this patient receiving both prednisone and acetylsalicylic acid. No antiinflammatory treatment was given to patients with chorea. After a mean follow-up of 4.52 months, valvar regurgitation disappeared in 4 patients, including the one with migratory arthralgia and no other major criterions. All six patients with chorea and silent carditis still have mitral insufficiency. Conclusion: Acute rheumatic fever without clinical carditis is not a benign entity. Doppler echocardiographic findings of subclinical valvar insufficiency, therefore, should be considered as carditis when seeking to establish the diagnosis of acute rheumatic fever.