The 9th Landwehr Division served on the Western Front, holding a sector in the Argonne Forest. From September to November 1915, it saw action in the Second Battle of Champagne. From July to September 1916, it was involved in the Battle of Verdun. It was peripherally involved in the Second Battle of the Marne in July 1918. Late in 1918, it faced the Allied Meuse-Argonne Offensive. Allied intelligence rated the division as fourth class; it was considered primarily a sector holding division and not an offensive formation but "on the defensive it showed some fighting ability.