Most boys afflicted with panhypogammaglobulinemia, also known as X-linked agammaglobulinemia, remain healthy during the first 6 to 12 months of life because of protection by maternally transmitted IgG antibodies. Thereafter, they repeatedly acquire infections with high-grade pathogens, such as pneumococci, streptococci, and hemophilus unless given antibiotics or immunoglobulin replacement therapy. We experienced a case of panhypogammaglobulinemia in a 4 years old boy. He had been suffered from recurrent upper respiratory tract infection, otitis media and pneumonia since late infancy. He was admitted due to right pleural effusion with pneumonia, and streptococcus pneumoniae was isolated from pleural fluid and blood cultures. His immune status revealed panhypogammaglobulinemia and deficiency in mature B lymphocyte. He was treated with appropriate antibiotics therapy, but showed poor responses. He was transferred to department of thoracic surgery, and received minithoracotomy (decortication) operation. He was successfully treated with operation, antibiotics, and IV gammaglobulin infusions. Now he is being followed with periodic IV gammaglobulin replacement therapy.