Memory and remembrance have a pivotal role in O'Neill's dramatic art. What has not been adequately appreciated and analyzed is that how far O'Neill's art stands as a reflection on trauma generally. In the first place the paper analyses that in line with modern concern with memory and trauma, O'Neill is essentially and predominantly concerned with the personal/subjective and not with the collective memory. Secondly the remembrance is charged with traumatic effect and the personas conduct in the plays like Strange Interlude and Long Day's Journey into Night is an illustration of trauma that expresses itself instantly as well as belatedly to mar human behaviour with variable degree of psychopathology. The traumatized responses in his persona vary, but are definitely regressive assume psychotic urge for repetition that obstruct individual harmonious integration with the self and the others. The immediate impression in performing traumatized memory is that of "affected state" that displays such traumatized reactions as overwhelming depressive behaviour that is repetitive, overlapping and mar the linear life movement, generate shattering anxiety, and "plunging the person into a form of authentic being towards death". These responses are essentially post modern in nature. The analysis will conclude on the point that the plays do not make provision for the strategies for coping with the trauma that characterized classic and Shakespearean theatre.