This paper considers the condition of Multiple Personality Disorder (MPD), which is defined as a separation of alternating personalities by rigid boundaries and amnestic barriers. It is proposed that MPD represents the end of a continuum of a defensive dissociation of the self that can result when a child employs a dissociative splitting of self into more or less independent part selves due to overwhelming environmental circumstances. Four case examples are presented in support of this position. Case one presents an individual in whom hidden ego states emerged and displayed some behavioral control in the course of hypnotherapy. Cases two and three present individuals in whom dissociated part selves were responsible for much of the presenting symptomology, but who did not qualify for a diagnosis of multiple personality. Finally, case four presents an individual representing a multiple personality disorder. It is noted that, since only case four would qualify for the diagnosis of MPD as defined in the Diagnostic Statistical Manual of Mental Disorders, there is a need for greater sensitivity in the recognition and treatment of these disorders. The recognition of a continuum of dissociation of the self that extends into multiple personality disorder is suggested. A five-page bibliography concludes the report. (NB)