Hydrogen gas was produced from metal plating wastewater by electro hydrolysis. Wastewater contains chrome, copper and nickel metals which can accelerate the production of hydrogen gas. Effects of kind of metals, the voltage and reaction time on percent hydrogen gas (HGP) were investigated. After application of different DC voltages on each metallic wastewater, percent hydrogen gas (HGP), cumulative hydrogen gas volume (CHGV), hydrogen gas formation rate (HFR) and total organic carbon (TOC) removal were also evaluated. Hydrogen gas percent was obtained as %99 at 4 V for chrome plating wastewater while percent hydrogen gas was achieved as 50% H-2 gas at 4 V for copper and nickel metal plating wastewater. Maximum CHGV achieved with 4 V DC voltage for all metal plating wastewater. Maximum CHGV (4000 mL), HFR (985 mL H-2 d(-1)) and percent hydrogen gas (99%) was observed with chrome plating wastewater at 4 V DC voltage. Hydrogen gas produced from chrome metal plating wastewater using electro hydrolysis method can be efficiently used for fuel cells as a source due to nearly pure hydrogen gas. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.