Before matriculating at the Warsaw Theatre Academy, she attended an amateur ballet school and Dorota Pomykała's acting school in Katowice.
Buzek made her screen debut in 1997 in the Television Theatre play Perła / The Pearl directed by Piotr Mikucki, which was based on Madame de La Fayette's 17th century novel. Her film debut came that same year in Robert Gliński's Kochaj i rób co chcesz / Love Me and Do Whatever You Want. Two years later she graduated from the Warsaw Theatre Academy and played in Moralność pani Dulskiej / The Morality of Mrs. Dulska at Ateneum Theatre in Warsaw - one of the few theatre roles before switching to film and television. While some critics owed her sudden fame in great part to her father, then the Prime Minister of Poland, with time she managed to make a name for herself on her own through the quality of her performances.
Agata Buzek took part in many Polish and international productions, including La ballata dei lavavetri / The Window Cleaners' Ballad directed by Peter del Monte (Italy, 1998), Libre circulation / Open Borders directed by Jean-Marc Moutout (France, 2002), and Valerie directed by Birgit Möller (Germany, 2007). She also starred in films made by well-known directors, including Krzysztof Zanussi's Skarby ukryte / The Hidden Treasure (2000), Andrzej Wajda's Zemsta / The Revenge (2002) for which she was nominated Best Supporting Actress at the Polish Film Awards, Peter Greenaway's Nightwatching (2007), and Marleem Gorris's Within the Whirlwind (2008). The leading role in Borys Lankosz's widely acclaimed film Reverse (2009) earned Agata Buzek the award for Best Actress at the 34th Polish Film Festival in Gdynia and at the 12th Polish Eagle Awards that same year.
Although Buzek's breakthrough came with Robert Gliński's romantic comedy, it was the part of Klara played in Andrzej Wajda's film adaptation of Aleksander Fredro's 19th century comedy The Revenge which gave her the nomination for the Polish Eagle award. She continued to work in film productions - and as a fashion model - until the success of Borys Lankosz's Reverse finally brought her vast recognition and a number of awards, including Best Actress at the 2010 Polish Film Festival in Gdynia.
In an interview with Magda Sendecka for the monthly Kino, Buzek observed:
In Fredro's times, people probably had thoughts similar to ours. They were, however, engaged in different life situations. My aim was to give my protagonist some contemporary qualities. I believe that one would need a broad knowledge of the epoch in order to express complex emotions in a drama. Yet, the idea was to make the intentions clear. While playing Klara's part, I kept in mind that it was a comedy. However, my approach towards the protagonist was even more serious because of it. (Kino, No 7-8/2002).
At the same time, she emphasised that it was not so much the director's choice as her own, which the director approved.
The success of Zemsta / The Revenge increased the critics' and a two-million audience's appetite for more films with Buzek. However by that time, Agata Buzek had already settled in Paris where she became…a fashion model. In an interview with Piotr Pacewicz for Gazeta Wyborcza Buzek admitted:
It was my idea to go to Paris. I was already 23. I earned my diploma. And in the fashion industry they do the make up for you, they tell you what to wear and your only task is to walk back and forth. Therefore, I used to give myself acting tasks, e.g. you are the queen and you cannot let anybody tell that you have just murdered the king. (Wysokie obcasy, No 46/2009).
And yet, the catwalk job was not enough to satisfy the young actress's ambitions. In July 2004, she established a foundation in Warsaw called Przestrzeń Wymiany Działań ARTERIA / Activity Exchange Zone ARTERIA to initiate and support young artists' projects and social activities. Agata Buzek engages herself not only in the theatrical projects of the foundation, but she also realizes her own passions in terms of social activities. She has supported the orange revolution in Ukraine (while organising a volunteers' trip to Kiev she met her husband), fought for human rights in Belarus and, as a vegetarian, for animals' rights. Buzek is an ambassador of Water Campaign organised by the Polish Humanitarian Action which sponsors a well construction in Sudan. As important as the actress’s achievements in the field of social activities are those noted by Jacek Sieradzki, a theatre critic for Polityka in Subiektywny spis aktorów teatralnych / Subjective List of Theatre Actors,
She returned to the stage after a lengthy absence with a bit part in a television production of Petr Zelenka's Tales of Ordinary Madness directed by Łukasz Kos and the part of Carol in Sallinger, Koltes's early play, so far not staged in Poland. The latter role has in particular reminded us of Buzek's acting talent, which is often lost due to miscasting. Sallinger was staged at the Nowa Praga Theatre in Fabryka Trzciny Arts Centre by an ensemble crazily called Activity Exchange Zone ARTERIA which attempts to find a way for fulfilling their high ambitions for which there is less and less space at the theatres in Warsaw. (Polityka, No 33/2005)