A case of Campylobacter jejuni (C. jejuni) myocarditis in a young man is described. C. jejuni was isolated from the patient's stools and he developed specific antibodies to this organism. Tests for other etiological agents (Salmonella, Shigella, Brucella abortus, beta-hemolytic streptococcus Group A, Treponema pallidum and coxsackievirus B) proved negative.