She is noted for her ultimately successful legal campaign to reclaim from the Government of Austria five family-owned paintings by the artist Gustav Klimt that were stolen by the Nazis during World War II.

[2][3] She was a niece of Adele Bloch-Bauer, a wealthy Jewish patron of the arts who served as the model for some of Klimt's best-known paintings and who hosted a Viennese salon that regularly attracted the most prominent artists of the day, including Gustav Mahler, Richard Strauss, Arthur Schnitzler, Johannes Brahms, Franz Werfel, Alma Mahler, Leo Slezak, Otto Wagner, George Minne, Karl Renner, Julius Tandler, and Klimt.

Fredrick was released and the couple fled, making a harrowing escape, leaving behind home, loved ones, and property (including jewelry that later found its way into the collection of Hermann Göring).

Traveling by way of Liverpool, England, they reached the United States and settled first in Fall River, Massachusetts, and finally in the Los Angeles neighborhood of Cheviot Hills.

[8] Shortly after Maria arrived in Los Angeles in 1942, Bernhard Altmann mailed her a sweater made of cashmere wool – a luxury fabric not yet widely available in the United States – accompanied with the note: "See what you can do with this."

Following the Anschluss of 1938 and Ferdinand's flight from Austria, the paintings were looted, initially falling into the hands of a Nazi lawyer.

By opening the archives of the Ministry of Culture for the first time, the new law enabled Austrian investigative journalist Hubertus Czernin to discover that, contrary to what had been generally assumed, Ferdinand Bloch-Bauer had never donated the paintings to the state museum.

[18] In November 2006, Adele Bloch-Bauer II was sold at auction at Christie's in New York to an undisclosed buyer, fetching almost $88 million.

[20][21] Altmann died on February 7, 2011, at her home in the Cheviot Hills neighborhood of Los Angeles, 11 days shy of her 95th birthday.

Adele's Wish, released in 2008 by filmmaker Terrence Turner, features interviews with Altmann, Schoenberg, and leading experts from around the world.

[24] Altmann is portrayed in the 2012 memoir The Accidental Caregiver by Gregor Collins, which documents their chance meeting and three years together, ending at her death in 2011.

[27] Laurie Lico Albanese's 2017 historical fiction novel, Stolen Beauty, tells the story of Maria Altmann and her aunt Adele Bloch-Bauer.