The invention relates to a method for the synthesis of acrolein by means of dehydration of the glycerol in the presence of a solid acid catalyst having a Hammett acidity of less than +2, such as sulfated zirconium oxides, phosphated zirconium oxides, tungstated zirconium oxides, silicated zirconium oxides, sulfated tin or titanium oxides, phosphated aluminas or silicas, doped iron phosphates, and phosphotungstic or silicotungstic acid salts placed in a reactive medium comprising a gaseous phase containing between 1 and 3000 ppm of an acid compound according to the Pearson classification, selected, for example, from SO3, SO2, and NO2, the dehydration reaction being carried out either in a gaseous phase or in a liquid phase.