The effect of hybrid inhibitor based on Gum arabic (GA, naturally occurring polymer) and zinc oxide on the corrosion of aluminium as galvanic anode in 4 M KOH was studied using hydrogen evolution experiment, electrochemical measurements, and surface analysis method. The results obtained showed that the combination of GA and zinc oxide operates as a hybrid inhibitor that effectively reduces self-corrosion of the aluminium anodes and increases inhibition efficiency (IE%) by increasing the concentration of GA. Also in the solutions containing ZnO/GA hybrid inhibitor, corrosion current decreases with GA concentration increment and its inhibition effect practically does not descend over time. The galvanostatic discharge shows that the additives suppress the hydrogen evolution and enhance the anodic utilization rate. In addition, the morphology and composition analysis of the aluminium surface suggest that the presence of GA promotes the deposition of zinc on the aluminium surface to be homogenized and more stable.