There is no precise definition for severe community-acquired pneumonia (SEHP), but there are a number of factors which are associated with a greater severity, and which therefore recommended the admission of these patients in an intensive care unit (ICU). In the present article, we mainly refer to SEHP in the immune competent population. SEHP makes up 8-10% of the total number of admissions of an ICU although this depends greatly on the type of unit concerned. The majority of patients admitted, do so because they need mechanical ventilation, because they present a shock situation, or because they develop a multi-organ failure in the course of the disease. The battery of usual tests recommended basically includes a chest x-ray, arterial gas, a count of red and white blood cells, biochemical profile, blood cultures, analysis and culture of the pleural liquid (if this is present), and respiratory samples. The therapeutic strategies tend to guarantee the simultaneous coverage of S. pneumoniae, H. influenzae, and the so-called atypical pathogens. Keeping in mind the considerable percentage of penicillin resistant pneumococcus existing in our country, in a general manner it is recommended to use a combination of a macrolide with a 3rd generation cephalosporin against this organism. They should be detected early, especially those situations in which there is respiratory failure and shock which shall require the use of mechanical ventilation and inotropics as well as an adequate monitoring.