Investigations were made by quartz crystal microgravimetry into mass changes of zinc electrodes in a NaCl solution caused by laser illumination (lambda = 488 nm). The mass of the dark electrode increases during zinc oxygen corrosion, which is indicative of the accumulation of corrosion products. A sudden increase in quartz oscillation frequency is observed at the beginning of illumination. This is also observed for the gold electrode. The effect of warming the solution is insufficient to cause the observed frequency increase. The rate of light-enhanced zinc corrosion was estimated as the difference between the frequency data obtained in both aerated and deaerated solutions. The best coincidence between corrosion ratios obtained from mass measurements and from voltammetric data is when ZnO is assumed to be the corrosion product.