Community-acquired bacterial pneumonia (CABP) is an important health care concern in the United States and worldwide, and is associated with significant morbidity, mortality, and health care expenditure. Streptococcus pneumoniae is the most frequent causative pathogen of CABP. Other common pathogens include Staphylococcus aureus, Haemophilus influenzae, Enterobacteriaceae, Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae. However, in clinical practice, the causative pathogen of CABP is most often not identified. Therefore, a common treatment approach for patients hospitalized with CABP is empiric antibiotic therapy with a β-lactam in combination with a macrolide, respiratory fluoroquinolones, or tetracyclines. An increase in the incidence of S. pneumoniae that is resistant to frequently used antibiotics, including β-lactams, macrolides, and tetracyclines, provides a challenge for the physician when selecting empiric antimicrobial therapy. When patients with CABP do not respond to initial therapy, they must be adequately reevaluated with further diagnostic testing, change in antimicrobial regimen, and/or transfer of the patient to a higher level of care. The role of hospital medicine physicians is crucial in treating patients who are hospitalized with CABP. An important focus of hospitalists is to provide care improvement in a way that addresses both patient and hospital needs. It is essential that the hospitalist provides best possible patient care, including adherence to quality measures, optimizing the patient's hospital length of stay, and arranging adequate post-discharge care in an effort to prevent readmission and provide appropriate ongoing outpatient care.