Attachment theory, developed by the British psychoanalyst John Bowlby and his American colleague Mary Ainsworth (Bowlby, Attachment and loss, 1969; Ainsworth et al., Patterns of attachment, 1978), aims at explaining why early interactions with caregivers have such a pervasive and lasting effect on personality development beyond childhood. Combining aspects of Darwinian evolutionary biology with social and personality psychology, attachment theory is built upon an inherent cross talk between disciplines. Attachment is conceptualized to rely upon both a behavioral system with a biological function and a cognitive substrate in terms of mental representations of person-environment interactions. Because of its comprehensive nature, attachment theory has become one of the most heavily researched conceptual frameworks in modern psychology (Mikulincer & Shaver, Attachment in adulthood: structure, dynamics, and change, 2007) and has recently inspired growing interest in the field of social neuroscience (Vrtička & Vuilleumier, Front Hum Neurosci 6, 212, 2012). Within the context of this book concerned with the missing link between neuroscience and social science, attachment theory offers a good practical example of a fruitful dialogue between disciplines helping to better understand human development. In the present chapter, I will first describe the fundamental assumptions of attachment theory and discuss their implications from an evolutionary as well as sociocultural perspective. I will then illustrate how attachment theory has inspired applied research in the field of social neuroscience and how the insights gained so far can inform possible prevention and intervention strategies in the context of mental and physical health and policy making across disciplines. Finally, I will comment on the remaining issues and future avenues of this still very young and exciting field of research termed "the social neuroscience of attachment."