We have carried out this research study because accidents are a serious public health problem in Mexico. They are the third overall mortality cause and the first among young adults. In addition, in our country, the study of posttraumatic stress disorder (PTSD) has not been focused sufficiently on accidents, not to speak of motor vehicles accidents. Among the different types of accidents, traffic accidents are placed at the top of the list. Aside from causing injuries and the loss of man hours at work, these accidents bring about emotional distress to affected individuals. Stress is a factor that triggers short-and medium-term consequences which are in turn reflected in the quality of fife of the patient and his/her family. PTSD is an anxiety disorder that causes psychosocial disfunctioning and appears due to the exposure to a stressor or traumatic event. It may come about in two ways: when the subject is a victim of a serious threat to his/her life or integrity and when the subject witnesses an event seriously affecting a third party. The main stressors may be natural phenomena, such as hurricanes and earthquakes, intentional attacks, such as rape or any form of criminal violence, and, as is the case here, from traumatic events caused by motor vehicles. The etiology of PTSD is multi-factorial and involves genetic, psychological, educational, and environmental aspects. It has three forms: severe, where the disorder appears immediately after the occurrence of the event or until a month later; chronic, lasting between one and three months; and delayed, where symptoms appear six months after the event. Our objective was to establish PTSD frequency in patients with physical injuries caused by motor vehicles accidents who were attended at the Regional Orthopaedics and Trauma Hospital "Adolfo Lopez Mateos". Together with the application of the scales, we were interested in making a description of the sociodemographical side of accidents, comparing the affect profile, and somehow defining the wide range of factors involved in the occurrence of this problem. For this, we devised a transversal and descriptive study with a non-probabilistic sampling.