With his wife Etta Stangl they founded in 1947 in Munich the Moderne Galerie Etta und Otto Stangl, an important gallery of the avant-garde after the Second World War in Germany.
[1] Etta and Otto Stangl were also involved in establishing the Franz Marc Museum in Kochel am See,[1] which opened in 1986.
Otto Stangl was one of the German Gallery owners who recovered the great painters of classical modernism for an entire generation of young artists that had been deprived of these works under the National Socialists.
[2] In 1948 when Hilla von Rebay organized “Zeitgenössische Kunst und Kunstpflege in USA” (“Contemporary Art and Art Care in USA”), Otto Stangl introduced to her the first non-objective German artists.
These artists, supported by Rebey and the Guggenheim Foundation, formed the important South German group Zen 49, that first appeared in June 1949 in the Munich Amerikahaus.