Intensive care units are a prime target for monitoring antibiotic consumption and conducting pharmacoeconomic studies because of their considerable antibiotic use. To evaluate the consumption and cost of antibiotics globally, per family, and for nosocomial and multidrug-resistant infections. This is a monocentric, retrospective, and observational study spanning one year (January 1st, 2018, to December 31st, 2018), and covering all patients hospitalized in the medical intensive care unit of Ibn Rochd University Hospital of Casablanca in Morocco. The global annual consumption of antibiotics accounted for 1410.21 defined daily doses (DDD) per 1000 bed-days from which β-lactams were the most consumed (768.95 DDD per 1000 bed-days). Community-acquired infections resulted in annual antibiotic consumption of 1340.82 vs 2483.69g DDD for nosocomial infections. Multidrug-resistant infections resulted in annual consumption of 737.5g DDD (52.2%). The global cost of prescribed antibiotics amounted to US$118,224.32. The consumption of β-lactams (38%) and fluoroquinolones (21%) combined cost ∼60% of the total budget. The cost spent on antibiotics for the treatment of nosocomial infections was US$57,544.11 vs 60,859.41 for the treatment of community-acquired infections. The cost of antibiotics prescribed for the treatment of multidrug-resistant infections reached US$47,744.14. This study made it possible to identify several aspects of misuse and overconsumption which allowed estimating certain expenses that could be entirely avoidable. As a result, this evaluation would be the first step towards the rationalization of antibiotic use.