The third child of Napoleon Berni and Margarita Picco, Deliso Antonio Berni was born in Rosario, province of Santa Fe, on May 14, 1905. His father, who worked as a taylor, was an Italian immigrant. Her mother descended from Piedmontese.
By 1914 Antonio began to work as an apprentice in the stainglasses workshop Buxadera y Cía. His first drawing lessons took place there. Around that time, due to family reasons, his father traveled to Italy and he was recruted in the army when World War I broke out. The family lost sight of him and later was informed of his death. In 1916 Berni took further drawing lessons at the Centre Català. Painters Eugenio Fornells and Enrique Munné were his teachers. He started high school at the Colegio Mariano Moreno, in Rosario.
His first experiences on landscape happened at the small farm of his maternal parents in Roldán, a rural village near Rosario, where he spendt lengthy stays.