- Background: The purpose of this study was to assess the prevalence of dissociative symptoms and post-traumatic experiences in an ambulatory setting. Method: The study was conducted in the ambulatory outpatient clinic of the Beersheva Mental Health Center. Over a period of six months new patients over 18 years of age were asked to participate in this survey. Patients completed questionnaires including the Dissociative experience Scale, trauma History Questionnaire, impact of event Scale, and Post-traumatic Diagnostic Scale. Results: A total of 505 patients were enrolled in the study, and 456 completed questionnaires were analyzed. of these, 442 (97%) participants reported at least one traumatic event during their lifetime. the traumatic events were experienced as meaningful and severe at the time of occurrence. the effects of sexual and childhood emotional abuse remained very intense throughout the victim's life and were viewed as powerful, significant experiences. on the other hand, traumatic experiences such as natural disasters and battle trauma were associated with longterm effects of relatively low intensity. Conclusions: The presence of undiagnosed posttraumatic stress disorder (PtSD) among patients in outpatient mental health clinics suggests that screening and diagnostic procedures for this condition be more carefully defined. our most important finding is the large impact of childhood trauma, especially sexual abuse, on later life. thus the prevention, early detection and treatment of child abuse in preventing long term psychopathology must be emphasized.