Abstract 1-Substituted 1H-tetrazole-5-thiols were efficiently converted into the corresponding 1-substituted 5-bromo-1H-tetrazoles by treatment with zinc(II) bromide and 50% hydrogen peroxide or 36% peracetic acid at 70–80 °C. In most cases, the 5-bromotetrazole products could be isolated simply by dilution of the reaction mixture with water followed by filtration and washing of the precipitated product