The subject of the present invention is a process for preparing pregelatinized high amylose starch, comprising the steps consisting of: forming a suspension comprising a high amylose starch and water; subjecting the said suspension to steam jet cooking at a temperature of between 125 and 135.degree. C. so as to obtain a pregelatinized high amylose starch paste; cooking and drying the said pregelatinized starch paste on a drum dryer at a pressure of between 2 and 10 bar, so as to obtain a pregelatinized high amylose starch. Its subject is also a pregelatinized high amylose starch, having an apparent density of less than 0.4 g/ml for a mean particle size of 100 micrometers. Its subject is in addition the use of such a starch for the manufacture of soft gelatin capsules or of hard gelatin capsules and the film-coating of pharmaceutical, dietary or agricultural solid forms.