The diversity and antibiotic resistance of the genus Aeromonas were studied in the inflow region and outflow region in three carp ponds of a commercial fish farm. The collected data indicated that the abundance of Aeromonas differed among the research water basins, regions and seasons. The results of the present study showed that Aeromonas inhabiting the water of the studied ponds strongly differed in the resistance level to tested antibiotics. This genus of bacteria was the most resistant to amoxicillin, ampicillin, clindamycin and penicillin and susceptible to streptomycin. The Aeromonas bacteria inhabiting the inflow were more resistant to tested antibiotics than those inhabiting the outflow of the studied ponds. Results of this study showed that multiple antibiotic resistance was observed among Aeromonas isolated from studied water basins which indicates the pollution of this environment with antibiotic substances. Aeromonas inhabiting the inflow and outflow regions of studied three carp ponds show different level resistence to antibiotics belonging to the different classes.