Perimyocarditis represents an inflammation of both the myocardium and pericardium. Although several causative agents have been recognized, pericarditis or myocarditis associated with rubella is an unusual complication. In a 29-year-old woman, left ventricular function transiently deteriorated accompanied by ongoing cardiac inflammation a few days after illness. The titer of rubella virus increased from seronegative to more than 32-fold during the admission, and a rise in specific antirubella virus antibody was present. The patient was suspected of having perimyocarditis associated with the rubella infection. The authors also present clinical features of rubella-associated perimyocarditis and myocarditis in the literature.