Caspar-Filser primarily painted flowers, gardens and landscapes, influenced equally by Impressionism and Expressionism.

In the wake of the Degenerate Art Exhibition in Munich on 19 July 1937, her artworks were removed from all museums and public collections and/or destroyed.

In 1959, she became the first woman painter to be awarded the Order of Merit of the Federal Republic of Germany.

She was awarded the Medal of the City of Paris at an exhibition at Musée National d'Art Moderne in 1961.

An exhibition of her paintings was held, for the first time in over two decades, at Hohenkarpfen Art Museum, from March to July 2013.