Community-acquired pneumonia is a frequent disease in outpatients; its incidence is highest among persons at the extremes of age. Hospitalization is rarely required. Since most clinical studies are performed with hospitalized patients, available data are not always representative of the general population. For instance, the importance of some organisms, such as Mycoplasma pneumoniae, is underestimated, and the severity of the prognosis is overestimated in the literature. Identification of the causative organism is usually not cost-effective in outpatients. Therefore, therapy is most often empirical. In Switzerland, the majority of patients can be successfully treated with macrolides. Antibiotics may also be chosen according to the most probable organisms in a given patient, based on his age and underlying diseases; this last strategy may be more logical from the point of view of public health.