In view of synthetic utility and biological importance of tetrazole derivatives, 1-phenylethyl undec-10-enoate, 1-phenylethyl (Z)-octadec-9-enoate and 1-phenylethyl (Z)-12hydroxyoctadec-9-enoate have been converted into their a-bromo 5-methyl tetrazole derivatives, using bromine, acetonitrile and sodium azide as reagents. The structure elucidation of the prepared compounds is based on elemental analysis and spectral data.