Lyme disease is a tick-borne spirochetal infection that may involve heart. The cardiac manifestations of Lyme disease including varying degrees of atrioventricular heart block occur within weeks to months of the infecting tick bite. This report describes a 43 year-old man with Lyme carditis who presented with complete heart block. The heart block resolved with ceftriaxone therapy. Lyme carditis should be considered in the differential diagnosis in patients who present with new onset advanced heart block.