A comparative study of the thermochemical behavior of cottonseed cake in static, nitrogen and steam atmospheres has been carried out. The influence of the different atmospheres in the yield and composition were observed. Pyrolysis under water vapor gave a rise in the yield as opposed to pyrolysis under static and nitrogen atmospheres. The elemental analyses of the pyrolysis oils were determined and the chemical compositions of the oils were investigated using chromatographic and spectroscopic techniques. The conversion to bio-oil and the chemical characterization has shown that the oils obtained from cottonseed cake can be used as a renewable fuel and chemical feedstock.