A novel copolymer based on sulfonated N-alkylated styrene-vinyltetrazole was synthesized. Copolymers were prepared by a 1,3-dipolar Huisgen cycloaddition reaction from their corresponding previously synthesized styrene-co-acrylonitrile copolymers and subsequently alkylated with aliphatic chains of 4, 6 and 8 carbon atoms. Finally, they were sulfonated using H2SO4 as sulfonating agent for 4 hours. The chemical structure of the copolymers was analyzed by FT-IR and 1H and 13C NMR, the thermal properties were evaluated by DSC and TGA. Membranes of the sulfonated copolymers were prepared using the casting method and their IEC evaluated by titration, water uptake (WU) by gravimetry and its electrochemical properties by EIS. Sulfonated membranes were also characterized mechanically by TMA. The sulfonated, non-sulfonated and alkylated copolymers exhibited the vibrational bands and chemical shifts with the signals corresponding to the functional groups associated with the involved comonomers, as well as the sulfonic group. Sulfonated copolymers exhibited an increase in Tg values compared to the non-sulfonated ones in addition to a good thermal stability for the desired application. Sulfonated and alkylated copolymers reduced their complex moduli (E*), but their values depended on the number of carbons in the aliphatic chain. Sulfonated copolymers exhibited high IEC values and a sulfonation degree of 38% was calculated. Proton conductivity for St/VTz-91:8C:S membrane (6.86x10-3 S.cm-1) was close to that obtained for the Nafion 117 membrane (7.6x10-3 S.cm-1). These copolymers are interesting for further investigation for their use as polymeric electrolytes for fuel cells.