Developmental trauma is a hidden pandemic leading to a multilayered array of negative outcomes across the lifespan, including critical health conditions and increased healthcare utilization. Such a scenario represents a major socio-economic burden with costs for health and social care and for society as a whole. A trauma-informed public health approach puts childhood adversities at the core of treatment and service provision. The chapter firstly outlines how a trauma-informed public health approach embedding the recognition of the Developmental Trauma Disorder diagnosis represents a major shift in conceptualizing health and social care provision and to recognizing the pervasiveness of adverse experiences. Secondly, the chapter elaborates a projective cost analysis to illustrate how the societal, health, and social care costs would be reduced if trauma-related policies were implemented. A multidisciplinary view—which includes an economic case aspect—could strengthen ACEs prevention efforts and could raise awareness about the problem.