Generally, infective endocarditis is found at the left side of the heart. The right side infective endocaritis accounts for only 5~10% of all cases of infective endocarditis. The right side infective endocarditis occurs especially among drug users employing intravenous injection. A typical site of infection is the tricupid valve, and isolated pulmonary valve involvement is rare. It is assumed that its rarity is due to the low pressure gradients within the right heart, the low prevalence of valve disease, and the lower oxygen content of the venous blood. We describe a case of isolated pulmonary valve endocarditis requiring valve replacement. Antibiotic therapy was conducted for 4 weeks before surgery and 2 weeks after surgery. Clinical course was favorable and the patent was discharged home 18 days after surgery.