The amino acid decarboxylating activity and production of biogenic amines, trimethylamine and ammonia by Morganella morganii (two strains), Klebsiella pneumoniae (three strains), Hafnia alvei (two strains), Enterococcus faecalis, Photobacterium phosphoreum, Micrococcus sp., Psychrobacter immobilis, Corynebacterium sp., Vibrio fischeri, Vibrio harveyi and Pseudomonas putida were investigated using a rapid HPLC method. In a laboratory medium containing amino acid (histidine, ornithine, lysine, tyrosine and arginine), not all bacterial strains produced the biogenic amines but most of them produced histamine, putrescine, cadaverine and ammonia. Cadaverine production by Klebsiella pneumoniae (8152), Klebsiella pneumoniae (673), Klebsiella pneumoniae (2122), Hafnia alvei (6578), Hafnia alvei (11999), Vibrio fischeri (25) Vibrio harveyi (42) and Pseudomonas putida (10936) was 531, 422, 532, 485, 472, 343, 547 and 343 mg/l, respectively in lysine decarboxylase broth. Tyramine was produced in highest concentration (526 mg/l) by Enterococcus faecalis (775). Agmatine was not produced apart from Psychrobacter immobilis (100) in an arginine decarboxylase broth.