Cardiac involvement during Legionnaires' disease has been rarely described; few cases of myocarditis, pericarditis and endocarditis were reported. We describe a case of myocarditis associated to pneumonia, with high antibody title suggesting a disease due to Legionella pneumophila. The patient had severe myocardial damage, with overt heart failure and important ECG and Doppler-echocardiographic abnormalities, without associated multiorgan involvement.