The terms unrepresented and unrepresented states are increasingly being referred to in psychoanalytic discourse, without our having established a generally agreed upon consensus about their definition, use or meaning. While these particular designations were never used by Freud, a careful reading of his work reveals them to be qualities that characterize the initial state of both the drive and perception. This paper attempts to place these terms in a clinically useful, metapsychological perspective by reviewing their conceptual origin in Freud and examining their elaboration and clinical relevance in the work of Bion, Winnicott, and Green. These concepts should prove especially useful for understanding and addressing problems presented by non-neurotic patients and psychic organizations and will help expand the reach and efficacy of psychoanalytic understanding and technique to increasing numbers of contemporary patients.