Anaerobic digestion is a natural process of organic substrates degradation using bacteria to produce biogas as renewable energy. Further to this clean energy, this process contributes to ensure a sustainable waste treatment process to protect the environment. The aim of the present work is to study at laboratory scale, the biogas production from co- digestion of fatty acids of slaughterhouse waste and digested sludge from wastewater treatment plant. During this experience, we followed the parameters that influence directly the anaerobic digestion, namely the evolution of pH and the optical density. In addition, a kinetic production of biogas was daily measured. These tests were successful in obtaining the combustible biogas with a high rate of methane