According to French doctrine, the economy of contract is one of the most influent judge-made law concept in the modern civil law of contracts. This flowing concept was firstly used in 1894 by French courts followed since 1919 by the Québec courts. However, the influence of the economy of contract is more significant in French law through its consecration by the constitutional judge. This study constitutes an introduction to the concept in comparative law. Therefore, it presents a high interest for the doctrine of contract in Québec where the notion is still unknown.