Background. Pneumonia is still a major global problem with high morbidity and mortality. The increasing number of pneumonia cases caused by bacteria, especially multidrug-resistant pathogens, increasing age of the population, patients with chronic disease (comorbid), and inappropriate antimicrobial therapy at initial administration make the treatment become less effective. These issues finally contribute to higher morbidity and mortality in cases of hospitalized pneumonia patients. Therefore, it is crucial to know the microbial pattern and select the therapy according to local antimicrobial sensitivity patterns. Method. A cross-sectional study was conducted for hospitalized pneumonia patients between January 2015 and December 2016 in Indonesia National Referral Infectious Disease Hospital. Data were collected from medical records to show patient characteristics, antimicrobial treatment data, culture examination, and bacterial sensitivity. Results. A total of 99 pneumonia patients required hospitalization and underwent sputum culture examination. The patients were mostly above 65 years old (32.3%) and male (57.6%). The most common comorbidities were pulmonary tuberculosis (21%), and the others were heart failure, chronic obstructive pulmonary disease (COPD), and HIV/AIDS. Based on the sputum culture, fungi were identified in most specimens (56%), while the bacteria identified were Klebsiella pneumoniae (14%), Acinetobacter sp. (12%), and Pseudomonas sp. (8%). Third-generation cephalosporin, such as ceftriaxone (50%), was commonly used as an antibiotic for pneumonia treatment. Conclusion. Most common bacteria isolated from sputum culture were Klebsiella pneumoniae which were more sensitive to the beta-lactam and aminoglycoside groups. The higher risk factors were age above 65 years old, being male, and having tuberculosis.