Various characteristics were determined for 222 aeromonads isolated from aquatic foods. Isolates were tested for resistance to 14 antimicrobial agents. Most of the isolates were resistant to penicillin A ( 95 % ). All strains were resistant to 10 ug O/129, and 67-100 % of the strains were resistant to 150 ug O/129. Most strains (50-100%) had weak hemolysis, except for A. hydrophila DNA group 1. Cytotoxic activity was found in most of the aeromonad, with the exception of some A. trota DNA group 13 and some A. media DNA group 5B strains. A higher occurrence of hemagglutination was found in A. hydrophila DNA group 1, A. media DNA group 5B and A. hydrophila like DNA group 2 strains. Most of A. hydrophila DNA group 1 ( 83 % ) showed a strong protease activity, but lower frequencies were found in other strains. A. trota DNA group 13 had the lowest lecithinase activity, while the other strains all demonstrated a high activity. A. hydrophila DNA group 1 demonstrated the highest nuclease activity and had a higher amylase activity than the others.