A young boy, who suffered from a febrile upper respiratory tract infection 10 days before admission, had symptoms of acute glomerulonephritis with decreased urine volume, swelling of the feet and dyspnea. Renal biopsy showed diffuse cellular proliferation of the glomeruli compatible with healing acute post infectious glomerulonephritis. The normal values ofASO tit¬ter and C$ degree suggested that the glomerulonephritis was non-streptococcal in origin. Although the symptoms of congestion has improved rapidly with therapy, the echocardiographic findings such as global hypokinesia, low ejection fraction and dilation of the right atrium, ST-T wave changes in the electrocardiography and elevated serum levels of CPK showed coexistence of myocarditis. Tests for neutralization showed a recent Coxsackie B2 or B3 virus infection.