Antibiotics are one of the greatest advances in modern medicine. Antibiotic resistance is one of the most serious threats to global health, aggravating the prognosis of immunocompromised patients, especially burn patients. Our objective was to study the consumption of antibiotics of critical importance according to the WHO and the correlation between antibiotic resistance in Pseudomonas æruginosa and the consumption of these antibiotics. Our study took place in the Medical Laboratory in collaboration with the Trauma and Burn Center's Burn Unit in Tunisia. In our retrospective study, 1384 non-repetitive strains of Pseudomonas æruginosa responsible for colonization or infection were included, between January 2012 and December 2019. Pseudomonas æruginosa was the most isolated bacterial strain in the service, with an average rate of 15.9% of the service's bacterial ecology. The antibiotic resistance rates tested were high: 77.1% to piperacillin-tazobactam, 56% to ceftazidime, 74.9% to imipenem, 78.8% to amikacin, 54.7% to ciprofloxacin and 32.8% to fosfomycin. Among our strains, 81.8% were multi drug-resistant strains. The analysis of the correlation between the level of consumption of antibiotics and the antibiotic resistance levels in Pseudomonas æruginosa showed that the increased consumption of piperacillin-tazobactam increased resistance not only to piperacillin-tazobactam but also to imipenem and amikacin as well as multi drug resistance. Similarly, the increase in the consumption of fosfomycin correlates with resistance to piperacillin-tazobactam and imipenem.