In the Seven Years' War, he joined the army of Schwerin in Bohemia and moved to winter quarters in Silesia. In March 1757 General Field Marshal Wilhelm Dietrich von Buddenbrock died and Krockow became chief of Buddenbrock old Cuirassier Regiment No. 1. He fought on 6 May 1757 in the Battle of Prague and on 18 June at Kolin. The regiment joined Frederick the Great's army in Lausitz, but later returned to Silesia to fight the Austrians with the Duke of Bevern. In the midst of battle, his horse was shot, which caused him to fall to the ground. A piece of shrapnel struck him and despite successful surgery, continued to cause him pain.