Biogenic amines are found in plants, animals, microorganisms, and humans and perform certain biological roles in the human body. Fish and shellfish products provide a rich source of good quality proteins, vitamins, minerals and PUFAs. Biogenic amines are generally formed by decarboxylation of amino acids. These are classified into 3 main groups. The biogenic amines play an important role in nucleic acid and protein synthesis, cell membrane stabilization, immune functions, and prevention of chronic diseases. Biogenic amine index (BAI) refers to the sum of histamine, putrescine, cadaverine and tyramine that has a quite good correlation with the organoleptic quality of tuna and sardines. The deterioration in the shellfish quality is also time and temperature dependent. In fishes and fish products, histamine is marked as the major criteria for decomposition whereas for shellfish, cadaverine, and putrescine served as a better indicator for hygienic quality.