In vitro flooding was used to treat a 14-yr-old male patient's posttraumatic stress disorder. Four traumatic scenes were identified, and stimulus-response imagery cues were presented. The S's progress was monitored through ratings of subjective units of disturbance. The S's level of anxiety, depression, assertion, and avoidance as well as his short-term memory and ability to concentrate were assessed 1 wk prior, immediately afterward, and 4 mo after treatment. Efficacy of the treatment was especially evident on the anxiety indices.