U-488 conducted three patrols. As a supply boat, she avoided combat.
On October 15, 1943, Maschinenmaat Karl Bergmann died of an illness. On November 25, 1943, Matrosenobergefreiter Heinz Heinlein fell overboard. He was rescued, but died of heart failure shortly afterwards.
On April 26, 1944, U-488 was sunk with all hands (64 dead) in the mid-Atlantic west of Cape Verde by depth charges from the US escort vessels USS Frost, Huse, Barber, and Snowden.