A process for producing a polyamide by reacting at least one aminonitrile with water has the following steps: (1) at least one aminonitrile is reacted with water at a temperature from 100 to 360 DEG C and pressure from 0.1 to 35.x 10 Pa, yielding a reaction mixture; (2) the reaction mixture is further reacted at a temperature from 150 to 400 DEG C and pressure lower than the pressure in step 1. The temperature and pressure are selected to yield a first gaseous phase and a first liquid or solid phase or a mixture of a first solid and a first liquid phase. The first gaseous phase is separated from the first liquid or solid phase or the mixture of a first liquid and a first solid phase is separated; and (3) the first liquid or solid phase or the mixture of a first liquid and first solid phase is mixed with a water-containing gaseous or liquid phase at a temperature from 150 to 360 DEG C and pressure from 0.1 to 30 x 10 Pa, yielding a product mixture. Also disclosed are other embodiments of this process and the thus produced polyamides.