A total of fifty-seven Pseudomonas aeruginosa isolates were collected from different sources of clinical (n=47) and environmental samples (n=10) during 2018, in Northern West Bank, Palestine. Molecular techniques were used to detect type III secretion exotoxin-encoding genes (T3SEEG), and clone identity. The antimicrobial susceptibility was carried out by the disk diffusion method. This study is aimed at comparing the distribution of the T3SEEG and antibiotic resistance between P. aeruginosa isolated from both sources. The correlation between T3SEEG and antibiotic resistance in both clinical and environmental isolates collected from a limited geographical area, in parallel, over a short period of time was also determined. In addition, clone identity between the clinical and environmental strains was determined. The results showed that all clinical and environmental P. aeruginosa isolates carried T3SEEG. ExoT was detected in all of the clinical and environmental isolates. The occurrence rates of exoY and exoS in P. aeruginosa isolates were 80.7 % and 36.8 %, respectively. More than one exotoxin gene was observed in 87 % of the clinical isolates and 70 % of the environmental isolates. The most common combination was exoT and exoY, with prevalence rates of 47 % and 50 % for the clinical and environmental isolates, respectively. ExoU was not detected in any isolate. There was no statistically significant difference between the distribution of T3SEEG according to the isolates’ source. There were no significant associations between the carriage of T3SEEG and resistance to some antimicrobials such as ciprofloxacin, norfloxacin, levofloxacin, aztreonam, tetracycline, and kanamycin. The profile of RAPD-PCR typing of 44 p. aeruginosa isolates (nine environmental isolates recovered from hospital sinks and thirty-five clinical isolates recovered from different hospitals) was clustered into three groups at a 96 % similarity level. There was no significant difference between the strains isolated from both of the environmental and clinical sources according to antibiotic resistance and the prevalence of T3SEEG. In conclusion, there was high similarity between P. aeruginosa strains isolated from both environmental and clinical sources. In addition, no significant differences in antibiotic resistance and the distribution of T3SEEG were observed among the isolates from both sources.