This article examines the family types identified by the French population census and by the Famille et Logements (family and housing) survey, drawing on and comparing all the information about family relations yielded by these two sources. Although the census in its current form (a rolling series of annual surveys) meets its remit of counting the number of persons living in France, taking the household as its observation unit, it is less good at describing families, especially when a housing unit is shared by several families, several generations, non-relatives and/or individuals living alternately in more than one household. This comparison sheds light on the causes of the divergences between the two sources. They stem from the differing objectives of the two data collection exercises, from the census data coding principles, which are based on the concept of the nuclear family, and from inaccurate declarations, each cause requiring its own solution. Despite the exhaustive nature of the census count, the international recommendations it follows do not allow marginal and/or emerging family forms to be adequately described, justifying the resumption of the Famille surveys coupled with the census.