Diagnosing post-traumatic stress disorder (PTSD) is challenging for several reasons: a lack of training in trauma assessment for most clinicians, underreporting and avoidance by patients, the overlapping of symptoms, and a high comorbidity with other mental disorders. Thus, a careful evaluation and differential diagnosis are essential for the treatment and management of this population. A concept of posttraumatic reaction in people with narcissistic vulnerability, called Trauma-Associated Narcissistic Symptoms (TANS) had appeared in the literature; this has not been, however, systemically investigated. This study examines three cases of TANS that developed after traumatic events such as traffic accidents and physical assault. TANS may mimic PTSD and can show similar features; however, a careful attention to the context and meaning of symptoms can help the clinicians in differentiating TANS from PTSD. Clinicians working with trauma and compensation evaluators should be on alert for this easily overlooked condition.