This article deals with the choice of witnesses at the civil wedding in the nineteenth century, in the french, dutch, belgian and italian cities, in order to know if this source can be useful for the understanding of urban personal networks. The various legal contexts influencing the selection of wedding witnesses are first analyzed. Afterwards we realize a first synthesis of all the recent studies on this topic, which demonstrates the importance of various factors as migration, neighborhood specificities, and the social condition of the spouses. We insist also on the relative lack of kin witnesses in the urban context. However the growing presence of kin witnesses and conversely the decline of “professional” witnesses in the second half of the century force us to analyze more precisely the multiple and moving social and cultural significations given by the families to this rather marginal aspect of the matrimonial ritualisation and to discuss the limits of its use as an indicator of the social networks of urban people.