This article presents a review of theoretical and methodological approaches to single fatherhood in foreign and Russian scientific literature. It also analyses statistical and demographic data on the prevalence of paternal families in Russia, studies the causes of the formation of single-father families, and examines their social status and problems. The author has сonducted content analysis of normative legal documents, materials from online communities on social media, and media publications. The article demonstrates that at the present stage, there is a diversification of family structures, including an increase of the proportion of single-parent paternal families. This phenomenon expands the traditional gender and paternal roles of men due to the emergence of new identities of the sole caregiver, the only person caring for children. The author has concluded that there is a need to clarify the concepts of “single father”, “single parent”, and “persons raising children without a mother” in legislation. A detailed examination of the underlying causes of the emergence of single-father families, the challenges they encounter, and the social infrastructure supporting single fathers has highlighted the necessity for the development of a novel national standard, namely “Social services for the population”. The term “social services for men” encompasses the scope and nature of social services for single fathers. The author underscores the necessity for unification of the activities of social institutions in regard to their work with single fathers, as well as the importance of training employees of social institutions working with families in contemporary standards, tools, and methods of work that take into account the specific needs and problems of paternal families and children.