For many decades, Ethanol has been used as Engine fuel as it has properties very similar to petrol, that make ethanol usable in engines with minor hardware modifications. It burns cleaner and is being blended in various ratios with petroleum origin transportation fuel all over the world. To overcome the ethanol shortage and in search for clean fuels, manufacturers shifted towards gaseous fuels like Liquified Petroleum Gas (LPG), Natural Gas, Methane, etc. Gaseous fuels are preferred over solid/liquid fuels as they give very less emissions. Biogas produced from organic waste is a promising alternative and renewable gaseous fuel which can be explored for use in IC engines. This review work provides a detailed summary of the work done in the gaseous fuel domain and particularly Bio-gas domain for its uses in IC engines. A substrate of Cow Dung mixed with other biowastes like rice husk or vegetable peelings can satisfactorily achieve a yield hike of 44% under controlled conditions. Presence of certain special microbes or catalyst the augments biogas generation. Biogas digesters fed with a substrate of 25% cow dung and 75% food waste reported 80% higher yield. Results of using this biogas mixed with CNG in engines is also elaborated.