A technical unit of measurement called the Defined Daily Dose (DDD) is defined as “the assumed average maintenance dose per day for a drug used for its main indication in adults”. Measuring drug utilization in DDD/100 bed-days is proposed by the WHO to analyze and compare the utilization of drugs. DDD can be used as a tool to analyze drug utilization with the ultimate goal of improving drug use. DDD are advantageous for comparing the use of drug in hospitals or regions. This comparison will provide valuable information when establishing appropriate usage level of drugs. Aims and Objectives: To evaluate and compare utilisation of β- lactam and Aminoglycosides antimicrobials in Medicine and urgery Intensive Care Unit. Objectives: 1. To determine the extent of DDD/100 bed days) use of β- lactam and Aminoglycosides AMS in medicine and surgery ICU 2. To compare utilisation of β-Lactam and Aminoglycoside antimicrobial in Medicine ICU and Surgery ICU. Type of study: It is a Cross sectional study. Study setting: The study was undertaken in Medicine I.C.U and Surgery I.C.U of central India Sample size: 357 patients. Methodology: The total dose of AMS (β lactam and Aminoglycoside) received by the patient during stay in MICU and SICU is calculated (Gram) for individual patient.Total dose (Gram) of individual AMS is calculated. ATC codes has been given to classify antibiotics (ATC-group J0; Antibacterial for systemic use). Then the data has been expressed as Defined Daily Dose per 100 Bed Days (DDD/100 Bed Days) based on the formula. Results and Observations: Total 11 Beta lactum and Aminoglycosides antimicrobials were used in 20 beded MICU. Among these AMS utilisation of injection Ceftriaxone (7.12) was highest followed by injection Cefotaxime (1.59), injection Piperacillin+ Tazobactum (1.42), injection Gentamycin (1.18). In SICU utilisation of injection Ceftriaxone (3.96) was highest followed by injection Piperacillin+ Tazobactum (2.29), injection Gentamycin (1.22). Conclusion: Drug utilization studies (DUR) using ATC/DDD system showed most commonly utilized (DDD/100 bed days) AMS in β - lactam class was Ceftriaxone (3rd generation cephalosporin) in SICU as well as MICU. But Piperacillin+tazobactum (broad spectrum penicillin) was maximally used in SICU (2.29) than MICU (1.42). While most commonly utilized Aminoglycosides AMS was Gentamycin followed by Amikacin with nearly equal utilisation in both ICUs (1.18 and 1.22 respectively).