Posttraumatic stress disorder (PTSD) and other stress related disorders are characterized by prominent psychophysiological symptoms, which are measured through changes mediated by the autonomous nervous system. Psychophysiological procedures in studies of acute and chronic trauma phase such as: baseline resting studies, startle reactivity studies, standardized trauma-related cues and idiographic-trauma cues have tried to gain insight into the neurobiology of the disorder. Psychophysiological parameters in PTSD are also considered as an additional method in diagnostics of PTSD. We will present results of previous studies as well as our research in search for psychophysiological indicators of PTSD. Our experience with applied psychophysiology (biofeedback) as an add-on therapy for psychiatric disorders will be discussed since it seems promising.