Posttraumatic flashbacks or revisualizations are a well-established symptom of posttraumatic stress disorder (PTSD). These episodes are capable of precipitating accidents. In this two-part study, the results of a previous pilot study which demonstrated an association between flashbacks and dream disturbances are confirmed. Such an association may be of use in prediction which PTSD patients are vulnerable to flashbacks. In addition, a comparison is made between flashback PTSD patients and other PTSD patients using the Impact of Event Scale. Flashback patients reported more frequent intrusive items on average and, specifically, more frequent daytime mental imagery. The implications of these findings are discussed.