Barbara Pec-Ślesicka was born on 24 August 1936. She graduated from the Film Production Organization Department at the National Film School in Łódź. In the years 1972–1983 she was the head of the production of Zespół Filmowy X, under which she supervised the production of Andrzej Wajda's films including The Wedding, Academy Award nominated Promised Land and Man of Marble, Man of Iron awarded in Cannes, and internationally recognised Danton, a Polish/French coproduction starring Andrzej Seweryn and Wojciech Pszoniak, winner of BAFTA in 1983.

She also worked with Agnieszka Holland, Andrzej Żuławski, Janusz Zaorski, Jan Kidawa-Błoński, Janusz Kijowski, and her son Maciej Ślesicki. She was a member of the Polish Filmmakers Association, the Polish Film Academy, and laureate of the Polish Filmmakers Association Award (2015), Silver Cross of Merit (1975), Knight's Cross (2001) and Officer's (2011) and the Order of Polonia Restituta.