A diagnosis of posttraumatic stress disorder (PTSD) encompasses several of the symptoms associated with the response to rape. The object of this study was to determine the incidence of PTSD among 51 rape victims and to compare the groups with and without PTSD with respect to the characteristics of the assaults. The results showed that 70% of the victims had PTSD and further suggested that PTSD was likely to be a long-term problem for these women. The results supported the view that psychological treatment approaches to rape victims should take into account the posttraumatic nature of the response. The incidence of rapes by strangers, of physical force being used, of weapons being displayed and of injuries being sustained by the victim were all higher in the group of women who had PTSD. These are all features that can be readily identified in the initial assessment of the rape victim and may help to identify the victims at risk of developing long-term psychological sequelae after rape. Appropriate therapeutic action taken early may influence the prognosis for a significant proportion of rape victims.