Smooth, compact, dendrite-free zinc deposits can be electrowon from acid zinc chloride electrolyte using a diaphragm cell featuring catholyte agitation by air sparging. A correlation exists between the degree of zinc deposition polarization and the zinc deposit structure and orientation that can be used to evaluate the effectiveness of addition agents and, ultimately, to control deposit quality. The effect of impurities on the current efficiency for zinc deposition and on the morphology and orientation of 24h zinc deposits is discussed.