A new jet-cooked starch-oil composite has been blended with a polyester polyol and then reacted with isocyanate to give a polyurethane foam. Infrared spectroscopy and microscopy have been used to examine the resultant products. Infrared spectra have shown the products contain the urethane structures and Light and electron microscopy have shown the differences in the cell wall structures and networks of the foams when compared to the control foams. Inclusion of the starch-oil composite in the formulation resulted in increased viscosity of the reaction mixture as well as a more irregular cellular structure and a rougher texture of the cured foam. Larger cells were more abundant and there was more evidence of tearing during expansion. The scanning electron photomicrographs show the open-cell structure of both the control and blended foams and their reticular network, which is more uniform in the control. This examination provides insight into the foaming process and provides information to make the necessary adjustments for acquiring the desired polymeric product. Incorporation of the starch-oil composite in polyurethane foams provides a new dimension of possibilities for enhancing their physical, functional, and environmental properties.