The aminopeptidase (apAC) gene from Aeromonas caviae T-64 was cloned and sequenced, This gene codes for a polypeptide composed of 393 amino acids with a calculated molecular mass of 42.2 kDa, The deduced polypeptide contains a putative signal sequence followed by a large proprotein which is thought to be processed to the mature 29.7 kDa protein. The deduced amino acid sequence showed 56.7% identity with that of the Vibrio proteolyticus aminopeptidase, a metalloenzyme with a capacity for binding two Zn2+ per molecule, The C-terminal ’helper domain’ considered as a requirement for protein excretion, associated with extracellular proteases From the Vibrionaceae family, was not found in apAC, Accordingly, apAC secretion is probably mediated by a different mechanism.