Abstract : The purpose of the present study were isolation of K. pneumoniae from clinical samples, determination of their antibiotic sensitivity against commonly prescribed antibiotics and evaluation of their ability to produce extended-spectrum beta-lactamase (ESBL), AmpC and Carbapenemase enzymes.The study was performed at the Department of Microbiology, Primeasia University, Banani, Dhaka-1213, Bangladesh. For isolation and identification of klebsiella, cultural characteristics on blood agar and MacConkey agar was observed along with different biochemical tests and the disc diffusion assay on Mueller-Hinton agar was done for determination of antibiotic sensitivity. Statistical analysis was done by employing Statistical Package for Social Science (SPSS Version 16) software. Total 120 sputum samples were collected of them 51 (42.5%) K. pneumoniae were identified. Sensitivity towards 15 differents antibiotics were determined by Kirby Bauer disc diffusion method. Third generation cephalosporin resistant bacteria were further analyzed to determine their extended-spectrum beta lactamases enzyme producing ability by double disc synergy test. AmpC and OXA-48 disc tests were used for detection of AmpC and Carbapenemase producer. Among 51 K. pneumoniae, 39 (76.5%), 31(60.8%), and 3(5.9%) were found ESBL, AmpC and Carbapenemase producer respectively. K. pneumoniae showed maximum sensitivity to Netilmicin (92.2%), Amikacin (90.1%), Meropenem (90.1%), Imipenem (88.2%), Ciprofloxacin (80.3%), L