The book centers on Paul Bäumer, a German soldier on the Western Front during World War I. Before the war, Paul lived with his parents and sister in a charming German village. He attended school, where the patriotic speeches of his teacher Kantorek led the whole class to volunteer for the Imperial German Army shortly after the start of the Great War. At the training camp, where they meet Himmelstoß, his class is scattered over the platoons amongst Frisian fishermen, peasants and labourers, with whom they soon become friends. Bäumer arrives at the Western Front with his friends and schoolmates (Leer, Müller, Kropp, Kemmerich and a number of other characters). There they meet Stanislaus Katczinsky, an older recalled reservist, nicknamed Kat, who becomes Paul's mentor.
"We are not youth any longer. We don't want to take the world by storm. We are fleeing from ourselves, from our life. We were eighteen and had begun to love life and the world; and we had to shoot it to pieces"
Paul Bäumer, chapter five (Arthur Wheen translation)
While fighting at the front, Bäumer and his comrades engage in frequent battles and endure the treacherous and filthy conditions of trench warfare. The battles fought here have no names and only meager pieces of land are gained, which are often lost again later. Remarque often refers to the living soldiers as old and dead, emotionally drained and shaken.
Paul visits home, and the contrast with civilian life highlights the cost of the war on his psyche. The town has not changed since he went off to war, but he has: he finds that he does "not belong here any more, it is a foreign world". Paul recovers the books and writings he had left in his childhood room, but finds his passion for literature to have been completely erased by the trauma of war. He feels disconnected from most of the townspeople, who ask him "stupid and distressing" questions about his experiences or lecture him about strategy and advancing to Paris while insisting that Paul and his friends know only their "own little sector" but nothing of the big picture. Indeed, the only person he remains connected to is his dying mother, with whom he shares a tender yet restrained relationship. In the end, he concludes that he "ought never to have come [home] on leave".
Paul is glad to return and reunite with his comrades. Soon after, he volunteers to go on a patrol and kills a Frenchman in hand-to-hand combat for the first time. He watches the man die slowly in agony for hours. He is remorseful and devastated, asking for forgiveness from the man's corpse. He later confesses to Kat and Albert, who try to comfort him and reassure him that it is only part of the war. Paul and his company receive a temporary reprieve from the horrid rations and living conditions of the trenches when they are instead sent to a supply depot in an occupied French town. They enjoy food and luxuries taken from the depot or looted from the town but continue to lose men to Allied shelling, culminating in Paul and Albert being wounded while evacuating civilians and needing to be diverted to a Catholic hospital far behind the lines. Albert eventually has his leg amputated, whilst Paul is deemed fit for service and returned to the front.
By the closing months of the war, German morale is almost nonexistent as the men realize they are only fighting to delay an armistice. The Americans have recently joined the war as both they and the English begin outperforming the far more poorly equipped Germans. In despair Paul watches as his friends fall one by one. Kat's death is the last straw that finally causes Paul to lose his will to live. In the final chapter he comments that peace is coming soon but he does not see the future as bright and shining with hope. Paul feels that he has no aims left in life and that their generation will be different and misunderstood.
In October 1918 Paul is finally killed on a remarkably peaceful day. The situation report from the frontline states a simple phrase: "All quiet on the Western Front." Paul's corpse displays a calm expression on its face, "as though almost glad the end had come."
