Ladislaus spent the last years of his life wandering from place to place. Hungary's central government lost power because the prelates and the barons ruled the kingdom independently of the monarch. For example, Ivan Kőszegi and his brothers waged wars against Albert I, Duke of Austria, but Ladislaus did not intervene, although the Austrians captured at least 30 fortresses along the western borders.

Ladislaus, who had always been partial towards his Cuman subjects, was assassinated by three Cumans, named Árbóc, Törtel, and Kemence, at the castle of Körösszeg (now Cheresig in Romania) on 10 July 1290. Mizse and the Cuman Nicholas, who was the brother of Ladislaus's Cuman lover, took vengeance for Ladislaus's death, slaughtering the murderers. Archbishop Lodomer subsequently dispatched two monks to Vienna to inform Andrew of the king's death. With the monks' assistance, Andrew left his prison in disguise and hastened to Hungary.