The term unmentalized experience is defined, elaborated, explicated, and illustrated with clinical examples from the analysis of adult patients. The origins of the author's conceptualization of the term are traced from Freud's early notion of the “anxiety equivalent” through the work of present-day object relations theorists. A model for the somatic recording of early pre- and postnatal experience is derived from Stern's research in the field of infant development, and some implications for treatment are noted.