Pneumococcal disease, which includes pneumococcal pneumonia, meningitis, and bacteremia, is associated with substantial morbidity, mortality, and health care costs in adults. Advanced age, chronic lung or cardiovascular disease, immunosuppressive conditions, and smoking increase the risk for infection. Despite the availability of an effective pneumococcal polysaccharide vaccine (PPSV23), vaccination rates among adults remain suboptimal. This is of immediate concern given the current H1N1 pandemic, since secondary bacterial infection with Streptococcus pneumoniae is common and can contribute to morbidity and mortality. The Centers for Disease Control and Prevention has recently called for increased efforts to vaccinate recommended persons against pneumococcal disease. Long-term trends including the growth of the elderly population and an increase in the number of patients with chronic conditions also underscore the importance of improving pneumococcal vaccination rates. It is important for health care providers, public health officials, and policy makers to recognize the serious health impact of pneumococcal disease in adults and to ensure increased coverage; at present, this is the best way to protect against invasive pneumococcal infection and its consequences.