Anaerobic Digestion of agricultural wastes; animal wastes, energy crops and industrial wastes is a technology that produces biogas (Methane Rich Gas), a promising source of energy which is renewable as well as eco-friendly. This study was designed to determine the kinetics of agricultural wastes biogas production when inoculated with cow dung/poultry droppings under mesophilic conditions with 8% Total Solids and 55 days retention time. The modified first order kinetic model was developed to access the kinetics of the biodegradation of the digestion process. A plot of 1/t(ln(dyt/dt)) against 1/t from the model gives the rates of substrate biodegradability and removal of the biodegradable fractions of the substrate. The result shows that maize cobs (MC) has the highest short term biodegradability index of 1.5827 while bio-digester D (SB) has the lowest rate of the biodegradable fractions (k) of – 0.302 among all the substrates. Bio-digester C (Rice Straw) has the highest yield of biogas with cumulative volume of 692.9ml and an R2 value of 0.8424 while bio-digester D (Sugarcane Bagasse) has the least of 185.9ml and an R2 value of 0.6479.