Primary cardiac lymphoma is very rare, and the most common electrocardiographic finding in this condition is complete atrioventricular block. After electrolytic, metabolic, ischemic, infectious, and traumatic etiologies have been excluded, primary cardiac lymphoma should be consided as a possible cause of reversible atrioventricular block. Most patients with primary cardiac lymphoma are immunocompromised and have disease with a B-cell etiology. This is the first case report of a primary cardiac T-cell lymphoma with complete atrioventricular block and torsades de pointes in an immunocompetent patient who was successfully treated using chemotherapy.