Together with the rest of the Croatian government, Mandić left Zagreb on 8 May 1945 and withdrew towards the Austrian border. He surrendered to the British on 15 May and demanded political asylum. The British ignored his requests and handed him over to the Partisans three days later, on 18 May. Mandić was charged with various war crimes and put before a military tribunal in Zagreb. Mandić was convicted and sentenced to death on 6 June 1945. His execution was carried out the following day.