In 1920, the Treaty of Trianon assigned a small part of the territory of the county (a small area around Horgoš in northern Vojvodina) to the Kingdom of Serbs, Croats and Slovenes (renamed to Yugoslavia in 1929). The rest remained in Hungary.
After World War II, the southern part of former Csanád-Arad-Torontál county (the Hungarian part of pre-1918 Torontál county and the south-western part of pre-1918 Csanád county) was added to Csongrád county.