The play is set in the early 1600s during the Thirty Years' War between the Protestants and the Catholics. Mother Courage sells her wares to the soldiers from her wagon, with the help of her three children. She is not happy about the war, but she is a businesswoman first and foremost. The decisions she makes throughout the play seem self-serving, but in her mind she is making a living and protecting her children. Unfortunately, her attempts to be a clever negotiator ultimately backfire, and her choices affect her children.

Even though she is adamant about her son not joining the war, Eilif is recruited. As this happens, Mother Courage is distracted by another soldier, who gets her to barter over a belt. Her other son, Swiss Cheese, is captured by the Catholics and confesses to helping the Protestants. Mother Courage attempts to negotiate his release but will not give up her wagon. This choice leads to the death of Swiss Cheese. Eilif returns and still believes he is on the battlefield. He steals cattle, is caught, and is sentenced to death. Mother Courage decides to leave her daughter, Kattrin, with a peasant family, even after assuring Kattrin they need to stay together. She enters a Protestant town to gather supplies. Meanwhile, the Catholics have taken the peasant boy, to serve as a guide, from the family Kattrin is with. The Catholics are going to ambush the Protestant town. Kattrin beats a drum to try and warn the town and is shot by the Catholic soldiers.

Mother Courage is a complicated character. While we might not agree with her choices or parenting methods, in the end we share a level of heartache and respect for her.