AbstractThree groups of Vietnam‐era veterans were compared on the frequency of symptoms typical of the diagnostic criteria for Post Traumatic Stress Disorder (PTSD), a diagnostic category introduced in DSM III (N= 90). The three groups consisted of veterans who had experienced (a) a war‐related traumatic event; (b) a non‐war‐related traumatic event; or (c) no traumatic event. The results indicated that the two groups who experienced a traumatic event reported significantly more symptoms than the group who never experienced a traumatic event. Furthermore, the group who experienced a war‐related traumatic event reported more symptoms than the group who experienced a non‐war‐related traumatic event. These results support the val