Allicin, allyl-thiosulfinate, a pharmacologically active compound with considerable fungicidal, bactericidal, antioxidant and anticarcinogenic effects, was obtained by oxidizing allyl disulfide with acid hydrogen peroxide. The synthesis mechanism was studied by the ESR spin trap method. The kinetics of allicin synthesis was ascertained by determination of the concentration of the limiting reactant during the synthesis using HPLC and it was found that the allicin synthesis reaction was of zero order. The allicin obtained was determined using UV, FT-IR, MS, 1H and 13C NMR analysis.