This article documents the often spectacular rise of the share of cohabitation in the process of union formation in over 350 regions of 13 Latin American countries during the last 30 years of the 20th Century. To this end harmonized census microdata were utilized (IPUMS International). In many provinces, and especially those with larger Indian and black populations, cohabitation and visiting unions have always existed as alternatives to the classic “European” marriage. However, as the data from 3 or 4 census rounds indicate, the rise in cohabitation occurred both in such areas with “old cohabitation” practices and in those where cohabitation had remained much more exceptional till the 1970s. In other words, there is now a sizeable chunk of “new cohabitation” besides or on top of “old cohabitation”.