A case of acute trichinosis manifested intermittent second degree atrioventricular block of the Wenckebach type. Review of 1,039 published cases of trichinosis in which electrocardiographic evidence of myocardial involvement was sought shows an average involvement rate of 20%. The majority (53.5%) of these abnormalities are manifested as T-wave changes. Low voltage throughout the limb leads (15%), intraventricular (13.5%), and atrioventricular (10.5%) conduction disturbances comprise the bulk of the remaining cases. This is believed to be the first reported case of atrioventricular block in excess of first degree associated with acute trichinosis.