One of the major causes leading to increased antibiotic resistance is excess antimicrobial consumption. We have analysed the correlation between antibiotic use and frequency of carbapenem-resistant Pseudomonas aeruginosa (CRPA) strains in the general intensive care unit of a university hospital Antibiotic use was expressed as number DDD (daily defined doses)/100 occupied hospital bed-days (BD). CRPA incidence rates were determined by number of unique isolates reported to 100,000 BD. The average use of antibiotics between January and August 2008 was 174 DDD/100 BD. The first four most frequently prescribed antibiotics were as follows: first and second generation cephalosporins (47 DDD/100 BD), carbapenemns (29 DDD/100 BD), fluoroquinolones (26 DDD/100 BD) and glycopeptids (20 DDD/100 BD). Average monthly incidence rate of CRPA was 546/100,000 BD (319-773/100,000 BD. CI 95%). There was a correlation between CRPA incidence rate and carbapenem plus fluoroquinolone use (Pearson coefficient of correlation r = 0.7, p < 0.05). Our data showed that the evolution of CRPA incidence rates was related to carbapenem and fluoroquinolone use.