Bigamy has been a crime against morality since the earliest days of New France. Of the 385 cases identified in our study of bigamy in Quebec (1763–1960), although priests were often called on to attest to the validity of a marriage or the morality of their parishioners, very few of them played the role of informer. Rather, they turned to the criminal courts only when they were unable to quell a scandal by their own methods. It is apparent that not only did the Catholic Church prefer to handle this offence against monogamous marriage by itself, but most importantly, given the small number of cases taken before the criminal courts, it continued to exercise its monopoly over the institution of matrimony during the first half of the twentieth century, even though the civil authorities sometimes flouted canon law. At the individual level, we would note that the institution of marriage remained fundamental throughout the period studied.