Purpose: We propose in this paper to analyze what are the factors that influence knowledge transfer both intra and intergenerational in family firms. The main objective is to establish a framework that can be used later in empirical research, although we maintain a completely theoretical approach in this paper Design/methodology/approach: This study, which is a comprehensive framework characterized the knowledge transfer literature in family firms in terms of the factors influencing them, was developed by an extensive literature review. Findings: Based on an extensive literature review, we conclude that knowledge is best transferred when family members value the following factors: trust between family members, commitment to the family business, intergenerational relationships, intragenerational relationships, psychological ownership of the family business, successor’s aspects and training, predecessor involvement in the successor training, organizational culture and relationships with Family Business Associations. Research limitations/implications: The study demonstrates the extensiveness and variety of knowledge transfer research. However there is not the same situation in family firms’ field. For academics, these different factors can be used as a map for future empirical studies. Originality/value: There is a notable lack of research into knowledge practices in small and medium-sized enterprises and especially in family firms. Besides, there is a gap in the understanding of an effective way to transfer these resources across generations; actually, existing studies on knowledge management in family businesses are scarce. The main value of our paper is to fill out partially this gap.