OBJECTIVE: The relationship of possession of transitional objects to the borderline personality disorder diagnosis was explored in a psychiatric inpatient setting. It was hypothesized that a greater proportion of inpatients who bring objects of special meaning with them to the hospital have borderline personality disorder. METHOD: Psychiatric inpatients (N = 146) were administered a semistructured interview to determine the presence of special (i.e., transitional) objects in the hospital, at home, or during childhood. Borderline personality disorder was determined by criteria on a DSM-III-R borderline personality disorder checklist and by DSM-III-R discharge diagnosis. RESULTS: Significantly more patients who endorsed having transitional objects in the hospital or at home had the diagnosis of borderline personality disorder. Sensitivity, specificity, positive predictive power, and negative predictive power of the possession of the transitional object for the borderline personality disorder diagnosis were calculated. Specificity was higher than sensitivity, and negative predictive power was higher than positive predictive power in each instance. While these results suggest that absence of a transitional object is more likely to be associated with absence of borderline personality disorder than the presence of a transitional object is with the presence of borderline personality disorder, the sensitivity of a transitional object during adulthood to predict a diagnosis of borderline personality disorder was 63%, and the positive predictive power was 45%. CONCLUSIONS: A transitional object brought to the hospital may help remind the inpatient with borderline personality disorder of home or provide soothing during separation from home. The persistence of transitional objects into adulthood may inform the therapist of possible transference paradigms that may develop in treatment.Abstract Teaser