[6] Her older brother, Wolfgang Mückstein,[7] is a physician and politician who served as Minister of Social Affairs, Health, Care and Consumer Protection in Austria from 19 April 2021 until 8 March 2022.

[14] In 2010, she founded the work collective and production company La Banda Film together with Flavio Marchetti, Michael Schindegger and Natalie Schwager.

[9][15] In 2013, she directed and wrote the screenplay for her first feature film, Talea,[4] starring Nina Proll and Sophie Stockinger.

[24] From 22 September to 2 October 2022, Mückstein was a member of the Focus Competition jury of the Zurich Film Festival.

[36][37] No name was given, but the only event of that kind taking place in Austria that night was the premiere of Corsage in Vienna, which led to speculation that Mückstein was referring to someone who worked in that film.

[37] Mückstein's Instagram posts inspired several women to share their own experiences with sexual harassment, sexism, racism, homophobia and abuses of power in the Austrian film and theatre community, which Mückstein then shared anonymously on her Instagram account,[39] which generated a lot of debates, media attention and sparked a new wave of the #MeToo Movement in Austria.

One should stick to the facts, because passing on rumors can seriously damage people; I appreciate Katharina Mückstein extremely for her attitude and her commitment to film politics, we are definitely on the same side.

[37] Mückstein wrote in reference to the reasons why many of those affected do not want to speak out openly against perpetrators; "What is your feminism worth if it ends on the edge of your comfort zone?".