In 1914, when World War I began, many buildings in Nisko were destroyed by the Russian Army, which attacked Austria-Hungary.
In 1918, local Poles gained control over the government in Nisko and the village became part of the new-formed Second Polish Republic.
In newly restored Poland, Nisko was the seat of a county in Lwów Voivodeship, but remained a village until 20 October 1933.
In 1921, its population was over 5000.
On 19 January 1937 in Warsaw, a bill was signed, which created Southern Works (Zaklady Poludniowe) – a large steel plant, part of the Central Industrial Region.
On 20 March 1937, first pine trees were cut in a forest in the village of Plawo, a few kilometers north of Nisko.
In two years, a brand new city of Stalowa Wola was established around the plant.
It was a milestone in history of the town, because several projects were started in the area, such as a foundry and a power-plant in the forests on the western boundary of Nisko.
The programme of industrialization was stopped with the invasion of Poland by Nazi Germany and Soviet Union in September 1939.

During World War II, Nisko became the focus of the Nazi German Nisko und Lublin Plan of forcible relocation of about 95,000 Jews from all over occupied Poland and from abroad in the name of German Lebensraum.
Chief architect of the Holocaust, Adolf Eichmann, set up a transit camp in Nisko, from which the deportees were to be expelled eastward.
The town was an important center of the Home Army and Bataliony Chłopskie.
In 1944 - 1945, the Red Army and the Soviet NKVD arrested here a number of Poles, executing members of anti-Communist resistance.
In 1914, when World War I began, many buildings in Nisko were destroyed by the Russian Army, which attacked Austria-Hungary. In 1918, local Poles gained control over the government in Nisko and the village became part of the new-formed Second Polish Republic. In newly restored Poland, Nisko was the seat of a county in Lwów Voivodeship, but remained a village until 20 October 1933. In 1921, its population was over 5000. On 19 January 1937 in Warsaw, a bill was signed, which created Southern Works (Zaklady Poludniowe) – a large steel plant, part of the Central Industrial Region. On 20 March 1937, first pine trees were cut in a forest in the village of Plawo, a few kilometers north of Nisko. In two years, a brand new city of Stalowa Wola was established around the plant. It was a milestone in history of the town, because several projects were started in the area, such as a foundry and a power-plant in the forests on the western boundary of Nisko. The programme of industrialization was stopped with the invasion of Poland by Nazi Germany and Soviet Union in September 1939.
During World War II, Nisko became the focus of the Nazi German Nisko und Lublin Plan of forcible relocation of about 95,000 Jews from all over occupied Poland and from abroad in the name of German Lebensraum. Chief architect of the Holocaust, Adolf Eichmann, set up a transit camp in Nisko, from which the deportees were to be expelled eastward. The town was an important center of the Home Army and Bataliony Chłopskie. In 1944 - 1945, the Red Army and the Soviet NKVD arrested here a number of Poles, executing members of anti-Communist resistance.
Nisko