 In 1963, at Stockholm University, Fischer-Hjalmars became Sweden's first female professor of theoretical physics, where she was known as a popular lecturer.She succeeded Oskar Klein in the post and maintained Professorship till 1982.She was affiliated with the International Academy of Quantum Molecular Science (member), Royal Swedish Academy of Sciences (member), Royal Danish Academy of Sciences and Letters (member), World Academy of Art and Sciences (Fellow), and the International Council of Scientific Unions' Standing Committee on the Free Circulation of Scientists (chair).