*Théorie des situations didactiques* is a foundational work in the field of mathematics education, presenting Guy Brousseau’s influential theory of didactical situations. The book develops a framework for understanding how mathematical knowledge is taught, learned, and transformed within classroom settings. Rather than treating instruction as a simple transfer of information, it examines the roles of students, teachers, tasks, and institutional expectations in shaping mathematical understanding. Central to the work is the idea that learning occurs through carefully structured situations in which students engage with mathematical problems and develop knowledge through interaction with the learning environment. The text remains important for researchers and educators interested in the theory and practice of mathematics teaching, especially in French-language scholarship on didactics and curriculum design.