Kostek (Russian: Костек; Kumyk: Кёстек, Köstek) is a village (selo) in the Khasavyurt District of the Republic of Dagestan in Russia.

Nearby settlements include Aknada and Yazykovka (Akaro) to the northeast, Kurush to the north-west, Chontaul to the south, and Novo-Kostek to the south-east.

Residents — Kumyks.— Brockhaus and Efron Encyclopedic Dictionary.Kostek settlement is founded approximately in the 60s-70s of the 17th century by an Enderi prince Alish Khamzin.

It is situated near river Koysuv… The village stands on an open plain with approximately 200 houses which are made according to local traditions of clayed twisted rods.

By the beginning of the 20th century Kostek developed into a large settlement of Terek oblast where apart from Kumyks lived several Russian, German, Jew and Chechen families.

According to another version the settlement appeared after fusion of Shebarla-Evl and khutor "Kostiyn-Otar" Kosteki or Kostyukovskaya village on river Koysuv consists of about 300 homesteads.

Despite the fact that the creek of this river is owned by Shamkhal Tatarskiy and is often blocked by his men, Andreev and Kostek fishermen give their take to Armenians and Russian manufacturers.

The amount of supplies of this raw material for production of highly valued dye for textile industry of Russia constantly grew.

Therefore, in the 18th century such centres of local and external trade like Tarki,Aksai, Enderi and Kostek had a great impact on the development of economy of Northern Caucasus that met the vital interests both of Russia and the region.

It is also known that in the beginning of the 19th century the population of Enderi, Aksai and Kostek including Nogays sold in Kizlyar building timber, cheese, fish products, millet, etc.

Archival documents, reports of Karginskiy post in particular, which merchants frequented to get from Kostek to Kizlyar give an idea of goods they sold.

This circumstance worried imperial authorities who were afraid that bought in Kizlyar goods would be brought customs-free through these settlements (residents of which were nationals of Russian Empire) to Dagestan and further to Transcaucasus and Iran.

That's why contrary to the decrees that no duty should be collected from Russian nationals, the imperial administration demanded payment of fees from inhabitants of Enderi, Aksai and Kostek that obviously provoked grievance from their part.

Tsarist administration tried to justify its actions arguing that Kumyk rulers ask Russian merchants to pay fees when they pass through their lands.

All these facts may lead to a conclusion that trade relations of Enderi, Aksai and Kostek with Kizlyar became more stable and diverse in the second half of the 18th century.

But some time later in the beginning of the 19th century Semyon Bronevskiy in his description of river Koysuv mentioned salmons and Kizlyar herring (shamaya).

The time passed and Kumyk families started living in the khutor and they called the Cossack simply "Kostik", then the name transformed into "Kostek".

Kidirniyazov in his book "Relations of Nogais with other people of Northern Caucasus and Russia in 16th – 19th centuries" wrote: "Settlement Kostek grew quickly.