The disciplines of psychiatry and psychotherapy have been significantly influenced by the pioneering contributions of Selma Fraiberg and Alicia F. Lieberman. Their work, especially in infant mental health, parent–child relationships, and trauma-informed care, remains profoundly impactful and relevant. This section will explore the enduring relevance of the contributions of some authors in the field of early childhood mental health, focusing more on the work of Selma Fraiberg and Alicia Lieberman. We attempt to help clinicians of multiple disciplines dealing with children integrate those concepts into current practice. Fraiberg was a pioneer in the field, together with others like Serge Lebovici, whose work is described in another chapter.