BACKGROUND: Influenza and pneumococcal vaccinations can reduce morbidity and mortality especially in the elderly and patients with chronic medical disease. The purpose of this study was to estimate vaccination coverage of these populations in a hospital setting. MATERIALS AND METHODS: We conducted a cross-sectional, descriptive study involving adult patients admitted to a 1,000-bed teaching hospital on April 15, 2013. We ascertained the information on whether the patient had received influenza vaccination within a year prior to admission or pneumococcal vaccination by interviewing each patient. RESULTS: A total of 491 eligible patients aged > or =50 years or with chronic medical illnesses were analyzed. The overall vaccination rate for influenza was 57.2%, and that of pneumococcus was 17.6% among the vaccine-eligible subjects. Influenza/pneumococcal vaccination rates of patients by disease were 62.8%/17.2% for diabetes, 53.3%/15.6% for malignancy, 67.6%/23.5% for chronic pulmonary disease, 66.7%/15.3% for chronic cardiovascular disease, 68.7%/26.9% for chronic renal disease, and 51.2%/18.6% for chronic hepatic disease. Young adult patients with chronic medical conditions were consistently less likely to receive influenza and pneumococcal vaccines irrespective of the underlying disease. CONCLUSION: The influenza and pneumococcal vaccine coverage rates among hospitalized patients were low in South Korea. This was especially the case for young adult patients with chronic medical illnesses.