Posttraumatic stress disorder(PTSD) is a psychiatric illness that results from exposure to serious threats of injury or death. In addition, dental phobia, which is suggested as a sub-threshold form of PTSD, may result from aversive or painful dental treatment. Patients with PTSD may present greater dental and behavioral challenges than other patients due to their mental illness, neglect of oral hygiene, and their medication. Dentists have to consider the challenges to provide these patients with proper dental treatment.