To study clinical and paraclinical manifestations of community acquired pneumonia (CAP), 75 patients hospitalized at National Hospital for Tropical Diseases were recruited from February 2011 to July 2012. All of patients were diagnosed CAP and severe CAP according to the criteria of the Infectious Diseases Society of America and American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults, 2007. Results: The most common symptoms of CAP were fever (98.6 percent), cough (90.6 percent), sputum (74.6 percent) and chest pain (68 percent). The rate of dyspnea and dyspnea feeling, confusing and myalgia in the severe CAP was significantly higher than those in non-severe CAP (dyspnea/dyspnea feeling 95.2 percent versus 46.3 percent
confusion 42.9 percent versus 1.9 percent
myalgia 57.9 percent versus 27.8 percent). 90.5 percent of severe CAP patients had multi/obed infiltrations. Thrombocyte and white blood cellls were significantly decreased but the levels of AST, ALT, Urea, CRP in blood were significantly increased in comparision with non-severe CAP. Alcohol dependence was a risk factor for severe CAP (OR=9.55
95 percent, CI=2.36-57.9).