To isolate, identify and speciate Klebsiella from various clinical samples and their Antimicrobial susceptibility pattern at tertiary care hospital, Chennai. Out of this 76 ESBL producing Klebsiella pneumoniae, 64(84%) were positive by Double Disc Synergy Test (DDST), 71(93%) by phenotypic confirmatory disc diffusion test (PCDDT) and 69(90.7%) by Etest strip method. Sensitivity was found to be maximum (93%) by PCDDT method, compared to other phenotypic methods such as DDST and Etest strip method. The Present study also highlights the need for the continued monitoring of Antimicrobial susceptibility patterns of important bacterial pathogens, so that rational antibiotic policies can be formulated.