Starch-based polyurethane foams were synthesized by reacting a mixture of starch and polycaprolactone triol with an aliphatic diisocyanate, in the presence of water as blowing agent. Some foams were also prepared by adding a certain amount of polyethyleneglycol. The reaction kinetics is affected by the presence of starch due to the higher viscosity related to the presence of the high molecular weight polysaccharide. Starch-based polyurethanes show higher glass transition temperatures and lower thermal stability. Cellular materials with different mechanical properties can be obtained by varying the amount of starch and by controlling the relative amount of polycaprolactone triol and polyethyleneglycol in the composition.