The aim of this article is to identify and define the diagnostic and therapeutic qualities of clay-work in contemporary conceptualization (attachment theory, object relations, and psychoanalytic theory). Three central features of clay-work are highlighted: (1) procedural expression through touch, movement, and the three-dimensional aspect; (2) the reflection of construction and deconstruction processes; and (3) the regression process. The authors differentiate six therapeutic factors that emerged from a review of the literature: facilitating expression of emotions, catharsis, rich and deep expressions, verbal communication, revealing unconscious material, and concretization and symbolization. Short case examples of therapeutic processes are described to illustrate these ideas.