Came from the Vilnius region. As a young girl, she supported her family with the daily chores on the farm and earned a living by weaving. Shortly before the war, she met her husband, but her marital happiness did not last long - after the outbreak of war, Korsak's husband was conscripted into the army and had to leave for the front. After the end of hostilities, her husband settled in Warsaw, which forced the artist to repatriate. Completing the repatriation formalities, she went to see an exhibition at the Trietriakov Gallery, which had a huge impact on the artist - after seeing the works, Korsak decided to paint herself. Initially, Maria Korsak created copies of paintings. In 1959, she enrolled at the Visual Arts Centre run by Barbara Jonscher, later continuing her education at the Visual Arts Centre in Warsaw's Bielany district. The artist was quickly noticed and gained recognition - her art began to sell, and her first major success was an exhibition in Miami at the Museum of Modern Art in 1963. The artist remained active until the very end of her life. She is considered one of the best Polish naive artists, and her works are in institutions such as the Ethnographic Museum in Warsaw, among others, and in many private collections.