The rationale underpinning the diagnosis of acute stress disorder is that cognitive mechanisms result in avoidant processing of aversive experiences. This study investigated acutely traumatized participants with either acute stress disorder (ASD; n = 15) or no ASD (n = 14) and nontraumatized comparison participants (n = 16). Participants were administered intermixed presentations on a computer screen of positive, neutral, and trauma-related words that were followed by instructions to either remember or forget each word. On a subsequent recall test, ASD participants displayed poorer recall of to-be-forgotten trauma-related words than did non-ASD participants. Severity of psychopathology was negatively correlated with to-be-remembered positive words. These findings are consistent with the proposal that people who develop ASD display an aptitude for superior forgetting of aversive material.