Differential scanning calorimetry (DSC) was used to investigate the thermal behaviour of sorbitol, mannitol, maltitol and to establish the following phase diagrams: sorbitol/mannitol, sorbitol/maltitol, sorbitol/water and maltitol/water. Pure sorbitol and maltitol (4-O alpha-glucopyranosyl-D-glucitol) vitrified uniquely upon cooling, once obtained under a melt form. Mannitol crystallized systematically in our conditions. These differences in behavior were discussed in terms of different molecular conformations in the liquid and crystalline states for sorbitol (hence, the difficulty to crystallize), whereas mannitol would present the same conformations in the two states. For sorbitol/mannitol and sorbitol/maltitol mixtures, the equilibrium phases could not be obtained (despite annealing experiments being carried out) and only the out of equilibrium phase diagrams were established. The tentative equilibrium sorbitol/water and mannitol/water phase diagrams were constructed but no hydrates were observed in our conditions (synthetic preparation of samples). The maltitol/water phase diagram presented simpler behavior than sorbitol/water despite the fact that maltitol is a larger and more complicated molecule (it is a derived sorbitol molecule).