The world now is looking for alternative resources of energy instead of using fossil fuels that contribute to the greenhouse gases and that are in depletion. This energy must be renewable and environment eco-friendly. The huge amounts of organic waste produced every year imposes to seek for a new approach and new methods to manage these tremendous quantities of organic waste dumped illegally into natural resources. Cow manure is considered one of the most abundant organic waste threating our world, especially that it produces greenhouse gases, malodours and destroy water and agricultural resources. From the other side, cow manure presents many properties that can be useful as renewable energy and soil organic natural amendment. Regarding the amount of cow manure produced, there is a significant possibility and opportunity for all researchers to work on this organic waste. One of the best biochemical methods used to manage cow manure is an-aerobic digestion. It is considered an attractive approach especially in terms of renewable energy (producing biogas and bio-fertilizers). This review article presents an overview of cow manure used as substrate and co-substrate in the anaerobic digestion process from different perspectives.