Developmental research on attachment has flourished in the past 15 years (C. H. Zeanah, 1996). However, there has been relatively scant empirical investigation of disorders in attachment. In this article, the pertinent developmental research on the attachment cycle is delineated and the current status of disordered attachment is examined. A particular focus is given to the conceptualization of the most severe form of disordered attachment, Reactive Attachment Disorder.