Abstract: A study of the susceptibility of Al-Zn alloys in molar concentrations of H2SO4 has been undertaken. Al-Zn alloys containing 1.0, 2.0, 2.5, 3.5 and 4.0% Zn were separately cast and machined to cylindrical test coupons of dimension range of about 17x16.8x15 mm and average surface area of about 12.71 cm2. They were weighed and immersed into beakers containing 0.5 and 1.0 M tetraoxosulphate (vi) acid; allowed to stand for six days with intermittent withdrawal of a set of test samples daily for weight loss measurement and corrosion penetration rate analysis. The result showed normal corrosion rate profile for passivating metals with increased severity of attack as both the alloy and the media concentration increased. In comparative terms, the 2.5% Zn alloy was the most severely attacked, a situation that could be attributed to increased grain boundary concentrations consequent upon the maximum solid solubility phenomenon (solvus line) in the duplex Al-Zn alloy system.