The aim of this meeting was to obtain a consensus on what constitutes good research practice in posttraumatic stress disorder (PTSD). Objectives were to review relevant parameters of trials, such as the patients recruited, the means of assessing PTSD at baseline, and the change in symptomatology in response to treatment, and to reach a consensus on the most appropriate parameters to use in future research. The bases for the discussion were the 1995 National Institute of Mental Health (NIMH) and the National Center for PTSD consensus on the assessment of PTSD, results of drug treatment trials, and information on the assessment scales used in PTSD research. © 1998, Cambridge University Press. All rights reserved.