ABSTRACT:The study was carried out in ASRAM hospital, eluru, over a period of 2 years from August 2012 to august 2014. The study was designated as prospective, observational, cohort study, which includes 100 cases of CAP selected on the basis of full filling the inclusion and exclusion criteria. Community acquired pneumonia continues to be a common clinical problem especially in elderly people. Males were more commonly affected than females but it was statistically not significant. Community acquired pneumonia is one of the common diagnosis in patients admitted in ICU and Emergency settings.DM and COPD are the most common co morbidities followed by rhinitis and smoking is the commonest risk factor for CAP. Cough, fever and expectoration are common and classical symptoms of pneumonia and significant number of patients with CAP can present with GI symptoms. Tachycardia, Tachypnea, Altered Mental Status, Hypotension, Cyanosis, acidosis, low albumin levels are few signs which indicate that illness is severe and critical and crepitations over chest on auscultation was the most common finding. Mean duration of stay was 8.99 days indicating it can cause significant loss in the form of economic loss if earning member of family is affected. Duration of stay was also prolonged in patients who are aged 65 and above, in patients who are undernourished, in patients with COPD and in patients who were treated with antibiotics prior to hospitalization but statistically these findings were not significant. In radiography Lower zones are most common site of involvement followed by mid and upper zones, Right lower zone was most common among all. Neutrophilic leucocytosis was the most common finding in haemogram. Gram positive organisms were more commonly seen than gram negative organisms on sputum gram's staining. Complications noticed were a)Need for ventilatory support both invasive or Non Invasive, b)Need for inotropic support for septic shock, c)Renal failure and need of temporary renal replacement, d)Sepsis and MODS, e) Prolonged ventilator support and need for Tracheostomy. CAP is a disease with significant mortality-18% in our study. It seems the resistance to penicillins and simple antibiotics may be rising. And need of extended spectrum pencillins and a higher antibiotic is also rising but there is a need for larger studies to confirm the same. CURB-65 class >3, PSI class>4 class were having sensitivity of 41.67% and 91.67% in predicting ICU admission with a specificity of 89.5% and 59.21 % respectively. Their sensitivity in predicting death was 44.40% and 88.9% with a specificity of 87.80% and 54.88% respectively. In both PSI scoring systems, mortality rate, need for intensive care unit (ICU) admission increased progressively with increasing scores but CURB-65 score did not show this correlation. PSI class of 4 and above is most sensitive and CURB 65 class of 3 and above is most specific in predicting both death and ICU admission. Both PSI and CURB 65 are complementary to each other in predicting mortality and ICU admiss...