We report the autopsy results of a patient with systemic sclerosis with myositis lesions in the skeletal muscles and myocardium. A 69-year-old Japanese woman developed congestive heart failure and died due to respiratory failure with restrictive hypoventilation. The heart at autopsy showed dilated ventricular hypertrophy, and histopathology of the heart exhibited diffuse replacement fibrosis resembling the lesion of ischemic heart diseases in addition to patchy fibrosis around myocardial fibers suggesting post-myocarditis-like fibrosis.