Between August 1939 and March 1941, U-37 conducted eleven combat patrols, sinking 53 merchant ships, for a total of ; and two warships, the British , and the French submarine Sfax (Q182). U-37 was then withdrawn from front-line service and assigned to training units until the end of the war. On 8 May 1945 the U-boat was scuttled in Sonderburg Bay, off Flensburg. U-37 was the sixth most successful U-boat in World War II.
