On 8 May 1945, Heszlényi, along with his son, József Heszlényi Jr., who served on the staff of his father, were captured by American troops. Heszlényi was then handed over to the Soviets, where he committed suicide by cutting his wrists with a razor blade on 2 June 1945 in Zwettl, Austria. On 19 June 1945 a military tribunal posthumously demoted and dishonorably discharged Heszlényi from the Hungarian Army.
Military career
Commanding Officer 23rd Infantry Brigade, November 1938 - 1 March 1940
Commanding Officer 2nd Motorized Brigade, 1 March 1940 - 1 November 1940
Deputy Chief of Supply Bureau, Ministry of Defense, 1 November 1940 - 1 May 1941
Chief of Supply Bureau, Ministry of Defense (HM/III), 1 May 1941 - 1 May 1942
Chief of Main Supply Bureau, Ministry of Defense, 1 May 1942 - December 1942
G.O.C. IV. Army Corps, December 1942 - September 1944
Fellgiebel, Walther-Peer (2000) [1986]. Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945 — Die Inhaber der höchsten Auszeichnung des Zweiten Weltkrieges aller Wehrmachtteile [The Bearers of the Knight's Cross of the Iron Cross 1939–1945 — The Owners of the Highest Award of the Second World War of all Wehrmacht Branches] (in German). Friedberg, Germany: Podzun-Pallas. ISBN978-3-7909-0284-6.
Kovács, Attila Ótott (2006). Die ungarischen Inhaber des Ritterkreuzes des Eisernen Kreuzes. Ranis: Scherzers Militaer-Verl. ISBN978-3-938845-02-8.