A crystallization method that comprises a step of providing a polyester comprising at least one 1,4:3,6-dianhydrohexitol unit, and a step of crystallizing this semi-crystalline polyester at a pressure of at least 600 mbar absolute. The method according to the invention makes it possible to strongly limit, or even eliminate, the phenomenon of polyester expansion during crystallization. Advantageously, the elimination of the expansion phenomenon through pressure conditions implemented according to the invention thus makes it possible to dispense with obtaining very fragile empty spheres that break when agitated and thus cause the formation of undesirable fine particles.