Production of biogas (methane-rich) by anaerobic digestion of organic waste provides a versatile energy source; methane can be used for the generation of renewable heat, electricity and fuel in replacement for fossil fuels, thus contributing to reducing greenhouse gas emissions and slowing down the climate change. Normally the process contributes to achieve two goals: to solve an environmental problem and simultaneously the economic valorization of a waste. In the last years, methane production through anaerobic digestion has been evaluated using different types of organic wastes: biological sludge, municipal solid waste, agricultural residues, animal farm waste, fruit processing waste, animal by-products, food waste, glycerol (biodiesel by-product) and algal biomass. This process is referred to as one of the most energy-efficient and environmentally-friendly ways of producing vehicle biofuel. Other possibility is the biogas production from agricultural residues that could be an interesting option for increasing the domestic biofuel production (in the EU, 1500 million tons of biomass could be anaerobically digested each year). The research team has been involved in different projects related to the valorisation of organic wastes (animal by-products, food residue, kiwi production waste, glycerol) by anaerobic digestion and, in the treatment of industrial effluents (dairy industry, agro food industry). Process optimization was taken into account to make it more attractive than current options. Research has focused on defining the best operating conditions to achieve the highest production of biogas from waste and evaluating its quality (methane content).