Background: Antimicrobial agents (AMAs) are the most frequently used drugs in the intensive care units (ICU) and regular auditing can prevent the development of resistance to AMAs, reduce the cost and incidence of adverse drug reactions. The present study was conducted to assess the drug utilisation pattern by measuring the defined daily dose (DDD) per 100 bed days for the AMAs used and their correlation with the APACHE score II.Methods: This was a prospective observational study, conducted in the Central ICU of SCB Medical College and Hospital, Cuttack, Odisha for 4 months. Data regarding demographic profile, diagnosis, APACHE II score, microbiologic investigation, length of stay, outcome and utilisation pattern of AMAs assessing anatomic therapeutic chemical (ATC) classification and measuring the antimicrobial consumption index (ACI) equal to DDD per 100 bed days were collected and subjected to descriptive analysis. Multinomial logistic regression model was used to predict probabilities of different possible outcomes of categorically distributed variables and independent variables.Results: Mean age of study population was 44.70±14.814 with male and female ratio of 1.63:1. Septicaemia was the most common cause of admission. AMAs were prescribed to 92.66% of patients during their stay which constitutes 37.32% of the total drugs used. The DDD per 100 bed days for the AMAs were 118.59 and ceftriaxone was found to be most frequently used. Patients having higher APACHE II score received more no of AMAs (4.20±1.30). Patients having low APACHE II Scores received less number of antibiotics as compared to patients having higher score.Conclusions: AMAs were prescribed to 92.66% patients in the central ICU and there is significant relation between the APACHE II score and number of AMAs prescribed.