1948–1989 Beet, blocks and a district seatRepa, paneláky a okresné mesto

Under communism Trebišov was made a district seat and grew the way district seats grew: apartment blocks, a hospital, schools, offices and a food-processing complex around the old refinery. Farming was collectivised — private strips were merged into cooperatives, which on this flat, fertile ground was at least technically efficient, whatever it did to the villages that had owned them. The broad-gauge railway from the Soviet border to the Košice steelworks was laid past the town in the mid-1960s. Trebišov went from under six thousand people before the war to more than twenty thousand.Za socializmu sa Trebišov stal okresným mestom a rástol tak, ako okresné mestá rástli: paneláky, nemocnica, školy, úrady a potravinársky kombinát okolo starého cukrovaru. Poľnohospodárstvo združstevnili — súkromné pásy polí zlúčili do družstiev, čo bolo na tejto rovnej úrodnej pôde aspoň technicky výhodné, nech to dedinám, ktoré tú pôdu vlastnili, urobilo čokoľvek. V polovici šesťdesiatych rokov postavili popri meste širokorozchodnú trať zo sovietskej hranice do košických železiarní. Z necelých šesťtisíc predvojnových obyvateľov sa Trebišov rozrástol na viac ako dvadsaťtisíc.