Issues relating to private family firm diversity and development are discussed with reference to established and emerging debates. Family firm assets and liabilities are highlighted. Key issues for family firms research and practice relating to family firm definition and family firm diversity are raised. Issues relating to context, culture and time are also discussed. Conceptual and empirical ‘types’ of family firms are illustrated. The contributions of ‘invisible’ members, women and couples in family firms are discussed. Various ownership forms relating to the perpetuation of family firms and business ownership transfer issues are highlighted. Articles in this special issue are then briefly summarized.