The objective of this work was to determine the best conditions for minimizing energy consumption in zinc electrowinning from alkaline solutions. The effects of several variables, i.e. hydroxide concentration (300–500 gl−1), current density (50–1000 A m−2), temperature (24–74°C), cathode material (magnesium, nickel, lead, stainless steels 304 and 316) and impurities (copper and arsenide) on current efficiency and cell voltage were investigated. The current efficiency was always 100% on magnesium except in the presence of arsenide (78% at 100 mg l−1). With cathode materials such as stainless steels 304 and 316, nickel and lead, hydrogen evolution was observed at the beginning of electrolysis. Hydroxide concentration did not have a significant effect on cell voltage.