Aeromonas spp. are Gram negative bacilli that are widely distributed globally in aquatic environments and cause infections in both human and cold-blooded animals. In this study, we aimed to investigate antimicrobial susceptibility of Aeromonas isolates from fish (Rainbow trout and Mullet) and rearing water in Turkey. A total of 45 Aeromonas isolates (20 A. sobria, 10 A. hydrophila, nine A. salmonicida, four A. bestiarum, two A. veroni) from three different geographic regions (Blacksea, Mediterrian, Aegean) of Turkey were included in the study. Bacterial susceptibilities of the isolates to 13 different antimicrobials were evaluated by disk diffusion method. Among the antimicrobials used in the study, gentamicin was the only antimicrobial agent to which all the isolates were susceptible. Similarly, florfenicol and ciprofloxacin were highly active (resistance rate 8.9%), whereas the lowest susceptibility rates were noted for amoxcillin (17.8%), ampicillin (22.2%), and oxolonic acid (35.6%). In conclusion, detection of different rate of drug resistance in the study, suggested that selection of appropriate antimicrobial agents is important for treatment of both fish and human diseases. Also in the light of the data an effective national antimicrobial resistance monitoring programs are required for Aeromonas spp.