Pneumonia acquired in Community (CAP) may be a primary disease occurring in healthy individuals or secondary to predisposing factors or comorbidity. Prevalence of CAP is 2.6 to 5% for all ages, in USA 12%, for over 65 years 30%. Streptococcus pneumoniae is the commonest pathogen 30-50%, H. influenzae in COPD, the atypical pneumonia Mycoplasma pn., M. catharralis, Legionella pn., Enterobacteria, anaerobics often in hospital survey. In children is different RSV, Parainfluenzae type 3, Rhinovirus in the first 2 years old. Others are S. pneumoniae, H. influenzae, Chlamydia sp., etc. Appropriate empiric antibiotic therapy choices are based in guidelines. The most common pathogen is S. pneumoniae, isolates raised resistance rates to Penicillin to 20-50%, 40% in our country and also to Macrolides, with potential clinical failure (21-40%). Specially in elderly people and with the comorbidity are recommended the 23 valent polysaccharide vaccine, effective in bacteremic pneumonia 70-80%. Is not effective in children under 2 years, for that is important conjugated vaccine Hib (toxoids T, D, CRM197, OMP Nm) to prevent carriers, otitis media and reduce exacerbation of these respiratory infections.