Hydrogen, as a clean fuel of future, is always counted environmentalist. However, production of hydrogen is not always green. Therefore, a need appeared to re-design the processes for terminating non-renewable resource dependency, minimizing wastes, increasing efficiency, and becoming greener. A systematic approach, Green Chemistry, which is based on 12 principles can be an instructive. This paper aimed to investigate the hydrogen production methods in accordance with green chemistry principles. Each method was evaluated for 12 principles to decide if they could meet the requirements or not. Hydrogen production methods investigated were classified under 4 groups according to the energy sources: electrical, thermal, hybrid and biological. After an overview of the main hydrogen production processes, we show that water electrolysis among electrical methods, biomass gasification as being CO2 neutral among thermal methods, photo electrochemical production among hybrid methods and bio-photolysis and photo fermentation among biological methods makes hydrogen production "green". (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.