Objectives: The aim of this study was to identify prevalence rates, sites and types of infection, the most common bacteria, and their antimicrobial resistance patterns, especially betalactamase producers present in Intensive care units (ICUs) of a tertiary care hospital. Methods: Clinical samples obtained over a period of 12months from January 2014 to December 2014 from six ICUs of a tertiary care hospital were analyzed. Identification of micro organisms to species level and their antimicrobial susceptibility testing was performed as per CLSI guidelines. For control, 500 samples each from the environment & staff of ICU were collected & processed in the same way.