Today Zemplín isn't an administrative region unlike its predecessor, but is divided between two of the 21 official tourism regions, Lower Zemplín and Upper Zemplín. Administratively, region is divided between Košice Region, which includes Trebišov and western part of Michalovce District (if Ung county is included, eastern part of Michalovce and whole Sobrance District also belong to Zemplín), and Prešov Region, fully including Humenné, Snina and Medzilaborce districts and from bigger part including Vranov nad Topľou and Stropkov districts. Major towns include Michalovce, Trebišov and Humenné.
Between 1879 and 1901 over 32,000 emigrated from the Slovak districts of Semplin to the USA.
During World War II, when Czechoslovakia was split temporarily, some of the Czechoslovak part of the county was occupied by Hungary under the First Vienna Award, and added to the counties Zemplén and Ung. After World War II, the pre-war border was restored, and the Hungarian county Zemplén merged with the county Borsod and the Hungarian part of Abov-Turňa to form the present Borsod-Abaúj-Zemplén county. Since the separation of Czechoslovakia into Slovakia and the Czech Republic in 1993, the northern part of Zemplín is part of Slovakia, divided between eastern parts Košice Region and Prešov Region.
See also: List of traditional regions of Slovakia