Diether von Roeder first saw action patrolling the skagerrak while alongside other German destroyers and inspecting merchant ships there on 28-30 September 1939. On 17-18 October 1939, Diether Von Roeder was among the destroyers conducting offensive mining operations off the Humber Estuary. These mines resulted in the sinking of seven ships totaling 25,825 tons. During Operation Weserbung the German invasion of Norway Diether von Roeder was assigned to Group 1, attacking Narvik. During the First Naval Battle of Narvik Diether von Roeder was the German picket ship stationed to warn of any British attempt to enter Narvik harbor. However, while Diether von Roeder was away refueling, and five British destroyers entered the harbor. In the ensuing battle Diether von Roeder was damaged. The Second Naval Battle of Narvik took place three days later. During the course of that battle Diether von Roeder damaged HMS Cossack (F03) but is damaged again and after the battle is scuttled.