The Ashchyozek (Kazakh: Ащыөзек, meaning "bitter river"; (Russian: Ащыозек), also known as "Gorkaya" (Горькая)[1] in Russian, is a river in the Zhanybek and Kaztal districts of West Kazakhstan Region, Kazakhstan.

[2][3] The river flows in the northern sector of the Caspian Depression, between the Volga and the Ural.

[4] The Ashchyozek has its origin in a source to the southeast of Borsy village in Zhanibek District, very close to the Kazakhstan–Russia border.

The river heads roughly southeastwards all along its course, meandering strongly in its last stretch.

The river is fed by snow and its waters are fresh in the spring, becoming salty and bitter in the summer, when it breaks up into disconnected pools.