Karpiński also participated in the Warsaw Uprising. On the first day of fighting, he was trapped weaponless with around 30 other soldiers in a hospital building on Koszykowa street after the weaponry supply had been mistakenly directed somewhere else. While evacuating the unit, Karpiński's group was caught under heavy fire, which resulted in most of the evacuees dead. Karpiński himself was shot with a 9mm caliber gun a bullet was stuck in his backbone but he survived. Found next day by the hospital's nurses, he received treatment but remained paralyzed. Released from hospital after the Uprising's collapse, he rejoined his family in Pruszków but remained unable to stand or walk. The family moved through Cracow and Zakopane to a small village of Murzasichle in the Tatras, where they remained through the rest of the war. During the course of the war, Karpiński was awarded the Cross of Valour three times.