Modeling of a fixed bed reactor for pyrolysis of cassava peels for the production of bio oil , bio char and bio gas has been studied. Model equations were developed using mass, energy and momentum balance equations coupled with rate equations, deduced from primary and secondary reaction mechanism. Simulation of the model equations was carried out at pyrolysis temperatures of 300oC, 400oC, 500oC and 600oC, adopting kinetic values in literatures, using the finite element method in COMSOL multiphysics programming environment. The results obtained showed decrease in char yield from 44.7% to 18.6% with increase in temperature, whilst bio gas increases from 16.7% to 54.4% as temperature increase from 300oC to 600oC. A maximum yield of bio oil was observed at 300oC which was comparable to results in literature. The simulation predicts the pyrolysis behavior of agricultural waste in a fixed bed reactor which will be useful for design and optimization purposes.