The 7th infantry division was sent to Slowakia on August 1, 1939, where it was mobilized on August 26. From September 1, 1939, the division took part in the Polish campaign. After advancing to the Jablunka pass and the Zwardoń saddle, it pursued Polish troops over the Dunajec and participated in the taking of Przemyśl.
Upon conclusion of the Polish campaign, the 7th infantry division was transferred to the western border of the German Reich. From there it took part in the Western campaign and on May 10, 1940, attacked through Löwen and Tournai in the Schelde sector, where it participated in the battle on the Schelde. Afterwards, the 7th infantry division crossed the Lys and took part in the fighting around Lille. Following the truce in June, the division remained stationed in northern France as an occupation troop.