The onset of global warming and depletion of fossil fuels is a serious cause of concern. Research and development to find alternative solutions to address these problems have been increasing at a rapid rate. It is desired that a fuel source is found that is capable of supplying the energy demands, while safeguarding the environment. Biohydrogen emerges as one such alternative source due to its high-energy density, zero-carbon emission, and its ability to cater to the requirements. This chapter discusses the production techniques for the synthesis of biohydrogen such as photolysis, dark fermentation, microbial electrolysis cells, and combined dark and photofermentation. It also discusses the enzymes involved and factors affecting hydrogen production. The bottlenecks in biohydrogen production for each process are critically reviewed, with challenges and benefits of each being presented as well.