This project aims to examine the gradual introduction of coeducation in French elementary schools during the 1960s. In the first part of the 20th century, French elementary schools were separated by gender, except in small villages. In the 1958-1959 school year, 30% of elementary schools were coeducational. The change was made at different times across France, before becoming compulsory in 1975. I plan to exploit this difference in the implementation to study the effect of mixed-gender schools on education, occupation and family composition.