After the conflict, Mikołajska studied chemistry at the Jagiellonian University from 1945 to 1946, as well as acting at the National Academy of Theatre Arts, which she graduated in 1947.

[1] In the 1970s, she begun being active in the dissident movement opposing the communist authoritarian government of the Polish People's Republic.

[4] Mikołajska was repeatedly harassed by the Security Service, and, beginning in 1976, she was blacklisted from performing in film, television, radio, and later, also in theatre.

[1] On 4 June 1989, shortly prior to her death, Mikołajska voted in the first partially free parliamentary election in the country.

[10] On 4 June 2012, in the Marshal Edward Rydz-Śmigły Park in Warsaw, near the senate building, was unvailed a monument dedicated to her, designed by Krystyna Fałdyga-Solska.