Pseudomonas aeruginosa is an opportunistic, nosocomial pathogenic microorganism and characteristically has an intrinsic resistance to multiple antibiotics. With the underlying objective of comparing the antimicrobial sensitivity profiles of populations originating from clinical and environmental samples, this study was designed to analyze the sensitivity profiles of 50 P. aeruginosa isolates belonging to 25 clinical and 25 environmental strains by employing the agar diffusion method for seven different antibiotics. PCR fingerprints were obtained using enterobacterial repetitive intergenic consensus (ERIC)-PCR to determine the genetical divergence of the isolates obtained from both groups. Twenty-two different antibiotypes were observed with the antibiotic resistance analysis. On the other hand, 18 of the 50 clones were grouped into eight clusters (similarity >90%) using ERIC-PCR analysis. Most of the isolates did not show a direct relationship between the band pattern and the resistance profile, possibly due to the great genetic plasticity of this microorganism. However, two P. aeruginosa strains belonging to the same genetic cluster had a 100% similarity level and the same antibiotic resistance profile. Other clusters showed overlapping resistance profiles differing in resistance to only one antibiotic. This result suggests that a genetic correlation between the isolates with similar antibiotic profiles is possible, even in the absence of a perfect match.