A 60-year-old man was admitted to our hospital for evaluation of intracardiac vegetative masses detected by echocardiography in September 2001. He had undergone surgery for oral cavity cancer in 1999. He presented with severe embolic symptoms including cerebral infarction, but had few symptoms of heart failure. Antibiotic therapy was started under the diagnosis of infective endocarditis, but the embolic symptoms persisted. An autopsy revealed that the intracardiac vegetative masses consisted of tumor cells originating from the oral cavity cancer. Intravascular tumor thrombi were also found widely distributed in other organs such as the liver, lung, spleen and kidney, and had similar histological features. This is a very rare case of cardiac metastases of oral cavity cancer without adhesion to the endocardium or other myocardial tissue.