In the beginning of 1922, she fled to Poland and in 1924 obtained Polish citizenship.
She with her husband established themselves in Szczekociny, but later lived near Łódź, in Brzeziny and Koluszki, where they worked as teachers.
In 1926 Kobro co-founded the Praesens group with architects Bohdan Lachert and Szymon Syrkus, but left the group in 1929 over content differences. Kobro, Strzemiński, painter Henryk Stażewski and poets Jan Brzękowski and Julian Przyboś then founded a.r. group, an acronym that is usually interpreted as "Revolutionary Artists" or "Real Avant-Garde".
In 1932, she and her husband joined the Abstraction-Création group. In 1937 Kobro signed the 1936 Dimensionist Manifesto published by Jean Arp, Marcel Duchamp and László Moholy-Nagy.
Under the influence of Constructivism she rejected individualism, subjectivism and expressionism, and instead postulated the absolute objectivism of form. Her main aim was to build an abstract work of art, based on universal and objective rules discovered through experimentation and analysis. Her sculpture conceptualized infinite space, which was to be seen as uniform and without focal or reference points (such as the origin of a coordinate system). Therefore, she strove to organize space in such a way that it would not be divided into space enclosed within form and excluded from it, but instead for the work to coexist with space and to allow space to penetrate it.
Escaping from the Second World War, which began in 1939, Katarzyna, along with her husband and daughter, runs to her family, to the Belarusian city of Vileyka.
Katarzhina Kobro died of cancer on February 21, 1951.