Abstract: A process for the production of 3-hydroxypropionitrile is provided. This process includes (a) reacting acrylonitrile with water at a defined molar ratio in the presence of a weak base under specific temperature and pressure conditions until a conversion in the range of about 40% to about 80% has been achieved; (b) after cooling the mixture obtained in (a), separating off its aqueous phase; (c) distilling off the acrylonitrile from the organic phase remaining after (b); (d) subjecting the mixture obtained in (c) to pyrolysis at specific temperature and pressure conditions in the presence of a basic catalyst to obtain a mixture consisting mainly of 3-hydroxypropionitrile and acrylonitrile; and (e) isolating the desired 3-hydroxypropionitrile by fractional distillation from the mixture obtained in (d). Such a process in which the basic aqueous phase and the acrylonitrile that has been distilled off are recycled represents a preferred embodiment.