A 31-year-old man with pneumonia and ampiema was treated with antibiotics and drainage. Hemophagocytic syndrome, characterized with pancytopenia was arised during this treatment. Nosocomial infection due to pancytopenia was treated with antibiotics. Hemophagocytic syndrome was recovered spontaneously after the treatment of this nosocomial infection. Such a severe hemophagocytic syndrome due to infection is a rare condition.