In August 1918 Lehár was decorated with the Knight's Cross of the Military Order of Maria Theresa in recognition of his services during the battles at Chodel south of Lublin in September 1914.

At the conclusion of hostilities of World War I, Lehár was able to move his regiment, without any casualties or desertion, back to Steinamanger (now Szombathely, Hungary).

After the dissolution of the Austro-Hungarian Empire, Oberst Anton Freiherr von Lehár decided to remain in Hungary and to fight again for the monarchy, in several roles and at various theatres of war.

[3] When the political turmoil had calmed down, Anton's brother Franz Lehár organized for the former general a job as director of the Society of Authors, Composers and Music Publishers in Berlin in 1926.

[3][20] Back in Vienna, Lehár founded the Chodel Music Publishing Company, but after it did not prosper, he decided to hand over the business to his brother in 1935.

When Germany occupied Austria in March 1938 (Anschluss), Lehár was ordered to move to Vienna, where the Gestapo could keep a closer eye on him and his wife for much of World War II.

[3][21] After Franz Lehár's death in October 1948, the former general became the administrator of his estate and spent the rest of his life guarding the rights and promoting the popularity of his brother's music.