We report the case of a 72-year-old man with pulmonary valve infective endocarditis, who complained of general malaise for 10 days. He was afebrile but there was no murmur. However, computed tomography showed a large mobile mass attached to the pulmonary valve, and echocardiography showed the same mass attached to the pulmonary valve but not to other valves. We needed to distinguish between vegetation, thrombus, and tumor. After a positive blood culture result, antibiotic treatment was started, but the mass increased in size since the time of hospitalization. We decided to remove the mass. Resection of the vegetation and pulmonary valve replacement were performed 11 days after hospitalization. After antibiotic treatment, the patient was discharged on postoperative day 30. This is a rare case in which infective endocarditis presented only at the pulmonary valve.