The effect of spices in decreasing histamine forming bacteria and thereby histamine formation is investigated. Quantitative determination of the biogenic amines was conducted using a Waters HPLC system with a Binary pump model M 515 and a C 18 Symmetry column with a flow rate of 1.5 ml/min. Spice treated tuna had significant difference from control sample in their histamine inhibition property (p<0.05%). Fish media inoculated with S.typhi and then treated with spices showed l log reduction in viable cell count for all tested spices except clove. Vibrio cholerae was susceptible to all treatments and after 24 hrs of spice treatment it was not detectable in the TCBS plates. S.flexnerii was also susceptible to the activity of spices. Statistical analysis showed that the control had a significant difference (p<0.05%) from the microbial number in fish media treated with clove. On SEM analysis, the untreated control showed rod shaped bacterial cells of Salmonella typhi measuring 1.32-1.65μm long. The growth in nutrient broth with 0.2% spice extract resulted in deformed cells. All the treated samples had pit formation suggesting localized collapse of cell wall. The cells were damaged beyond recognition in cardamom and oregano treated samples. The reduction in biogenic amine was found to be directly proportional to the reduction in histamine forming bacteria in the samples. The inhibitory ability of these spices to arrest toxic amine formation can be used beneficially in food industry.