A 1-year-5-months-old female who had cough, rhinorrhea and prolonged fever for 19 days was admitted to the intensive care unit due to exertional dyspnea. She was intubated promptly in virtue of hypotension and cyanosis. The physical examination demonstrated diminished breathing sound over the right lung and distant heart sound; echocardiogram showed cardiac tamponade. Further X ray study showed right hydropneumothorax and cardiomegaly. Pericardiocentesis and chest thoracostomy were performed, and subsequently all the cultures showed growth of Streptococcus pneumoniae. Antibiotics therapy was started promptly after admission. Further investigation indicated osteomyelitis of the right ilium, so that surgical debridement was done. The patient was discharged 54 days later with complete recovery. After following up for 18 months, no restrictive heart disease developed. Purulent pericarditis with cardiac tamponade is an extremely rare complication of pneumococcal infection.