We investigated the antibody response to a 23-valent pneumococcal polysaccharide vaccine (23PSV), in 151 patients (average age: 70 years old) with chronic respiratory disease. Serotype-specific IgG antibodies to 4 pneumococcal capsular polysaccharides (6B, 14, 19F, and 23F) were analyzed by ELISA before, and one month after, 23PSV vaccination in all patients. Patients showed a significant increase in specific IgG levels to Streptococcus pneumoniae after 23PSV vaccination (5.5 times-20.9 times). Even patients aged over 80, patients with respiratory failure, and patients receiving corticosteroid therapy developed a significant immunologic response to 23PSV. Local pain or induration occurred in 9.1-14.3% and fatigue or chills occurred in 0.7-6.5% of patients. All adverse reactions disappeared in 2 or 3 days and there was no severe adverse events. Further studies are needed to confirm the exact protective antibody level and to examine the decline of antibody level after vaccination.