The authors report the case of a 31 year old woman, admitted as an emergency for acute myopericarditis, in cardiogenic shock. Echocardiography showed severe left ventricular dysfunction associated with concentric biventricular hypertrophy with increased echogenicity of the myocardial walls. Poor response to treatment with intravenous inotropic drugs led to referral for biventricular circulatory assistance with a Biomedicus pump, which was withdrawn on the 9th day after recovery of normal left ventricular function. Myocardial biopsies showed massive interstitial inflammation with a predominance of eosinophilic cells suggesting a hypersensitivity reaction. Steroid therapy was prescribed when the results of biopsy were known and stopped after 6 months. This case emphasises the value of echocardiography and myocardial biopsy in diagnosis and treatment of acute myocarditis with cardiogenic shock.