Trauneck left the GDR in 1965.To Schoenberg's son-in-law Felix Greissle, he later explained the reason why he had left East Germany:
'Hanns [Eisler] helped me a bit later, but I could not bear it any longer, the regime worsened from year to year. In 1965 I got sick (jaundice) and after I recovered, I returned to Vienna.1
Trauneck then lived in Vienna as a retired 'musical director' in very reduced circumstances. His old friends from the Schoenberg Seminar, Erwin Ratz and Josef Polnauer, helped him ﬁnancially and he remained very active in his work in the cause of Arnold Schoenberg. He was one of the main initiators of the establishment in 1974 of the memorial centre in Schoenberg's house in Mödling. He was also one of the key organizers of the Schoenberg centenary anniversary which was celebrated the same year. Until his death in Vienna on 14 February 1975, he was an active member of the International Society for Contemporary Music. He was survived by his wife Lisbeth who later returned to South Africa.
Despite these many activities, Trauneck may have written his own epitaph shortly after his return from South Africa:
Reading it [a book on Webern] all the old life and pictures came back, it made me quite sad to feel how far, unmeasurably [sic] far, all this has become to me and how different it might have been, had I not left Vienna in 22 never to return. I really wonder what it is that drives me. Am I the wandering Jew, why have I never returned to my homeland and my mother tongue, why did I leave Vienna in hate, why did I admire great Germany only to find out that German people are the most brutal, hypocritical, backward people imaginable, flee in 38 with a curse, and now - should I say finally, because in a few weeks I'll be 60 and it isn't wise perhaps to make big moves at that age - I am back here.2