The frequency of antibiotic resistance was compared in Aeromonas spp. isolated from fresh and brackish water in Southern Turkey. A total of 97 Aeromonas spp. strains were isolated from four zones (three from fresh and one from brackish water). Most of the strains isolated from all samples were Aeromonas hydrophila (79.4%), while the amount of Aeromonas sobria and Aeromonas caviae, were rather lower in the samples examined (17.5% and 3.1% respectively). A high proportion of isolates from all water sources showed resistance to cephalotin (86.6%) and trimethoprim-sulphamethoxazole (69%). On the other hand, a low proportion of bacteria showed resistance to tetracycline (14.4%), chloramphenicol (11.3%), gentamicin (7.2%) and nitrofurantoin (6.8%). Only one strain showing resistance to amikacin was found. Multiple Antibiotic Resistance Index (MARI) to at least two antibiotics was highest in brackish water (zone 4), followed by fresh water (zone 3). MARI values ranging from 0.2 to 0.8 for the bacteria isolated from brackish water. This study suggest that, multiple antibiotic resistant Aeromonas spp., especially A. hydrophila, can be easily recovered from fresh and brackish water sources in Turkey and these sources may play as a reservoirs responsible for disease pathogen aeromonads.