During the War of Liberation in Yugoslavia (1941–1945), Nevenka Petrić was a fighter against the German occupiers and collaborators, and after a short while, she became the youth leader of her troop, battalion, unit, and later the Banja Luka district and the whole of central Bosnia. She was actively engaged in creating anti-fascist youth organizations in both free and occupied territories, among civilians and the army. There were two youth units in the beginning, in Banja Luka and Prnjavor, and later new units were created in central Bosnia—Vlašić, Travnik, Uzlomac, Doboj, Derventa, Tešanj and others, and significantly later central Bosnian brigades were formed: 14th, 18th and 19th. For her war service she received the Spomenica 1941 award and other medals and awards.