This article discusses the concept of Constitution in contemporary legal culture in Latin America. The thesis raised is that the notion of written Constitution, by itself, is insufficient to fully explain the constitutional reality and so it needs to be complemented. This complement is located outside the linguistic statements of the constitutional text and comprehend interpretations, customs and some features of constitutional discourse. If true, this thesis, she would explain in a better way the current praxis of Constitutional Law than the recourse to the sole idea of a written Constitution. Additionally, it would reveal a tendency towards convergence between Common Law and Civil Law countries, blurring this traditional distinction in western legal culture and leading to a Global Constitutional Law, a trend which would be also present in Latin America.