ZTS, ZTS Traktory Works of the Slovak Republic, is/was a builder of tractors. Based in Martin, Slovak Republic, ZTS began building tractors in 1973 in cooperation with Zetor. ZTS built many of the higher horsepower tractors for Zetor, which were sold under the Zetor, Zetor Crystal and Crystal brands, along with ZTS and possibly others. It was later known as ZTS Martin and ZTS-Tees Martin.