A 52-year-old man with neither congenital heart disease nor history of drug abuse had a spiking fever after dental treatment and was diagnosed with pneumonia at a local clinic. He was treated with antibiotics and his fever went down. Ten months later, he had again pyrexia and suffered from congestive heart failure. He admitted to our hospital and tricuspid valve endocarditis was proved by echocardiography. He was treated with penicillin. However, during the treatment, he developed a pulmonary embolism. So he underwent surgical treatment. We should take dental treatment into account one of predisposing causes of tricuspid endocarditis.