Acute rheumatoid fever continues to be a significant public health problem in developing countries. Cardiac involvement is responsible for morbidity and mortality. Endocardium, myocardium and pericardium may be involved. Mitral and aortic valve insufficiency, stenosis developing over time, congestive heart failure, myocarditis and pericarditis may be most frequently seen. Apart from these, many rhythm and conduction defects may also develop during the progress of disease. These include atrioventricular block at every degree, atrial or ventricular premature beats, accelerated nodal rhythm, supraventricular tachycardia and junctional and ventricular tachycardia. The possibility of patients developing Mobitz type I second degree atrioventricular block is very low. This article presents a patient identified to have a Mobitz type I atrioventricular block without cardiac involvement in the acute period and discusses this rarely seen condition in the light of literature data. Anahtar Kelimeler : acute rheumatoid fever, Mobitz type I block