Hydrogen gas can be produced by conventional methods such as thermo-chemical gasification, pyrolysis, solar gasification and supercritical conversion. Hydrogen productions through biological methods are an attractive and alternate method for the replacement of fossil fuel in future. In this review, the major biological processes discussed for hydrogen production are bio-photolysis of water by algae, dark fermentation, photo–fermentation of organic materials and the sequential dark and photo-fermentation processes. Major constraints in dark and photo-fermentative hydrogen production include the raw material cost, lower hydrogen yield and rate of hydrogen production. To overcome those constraints, intensive research works are strongly recommended to be carried out on the advancement of these processes. The review showed effective utilization of low cost substrate such as agricultural, food industry wastes and effluents such as diary industry wastewater for hydrogen production with inexpensive energy generation and simultaneous wastewater treatment. It reveals that the hydrogen yield could be even achieved greater with the effective pretreatment methods of inoculum and substrates. This review explores the recent status and developments that have been made to improve the hydrogen production particularly with pretreatment methods and gave an outline about the unit cost of various hydrogen production processes.