Posttraumatic stress disorder is a psychiatric disease that develops after an event threatening individual’s life and/or body integrity and affects the quality of life and social functioning of the individual. EMDR integrates the various well-known approaches such as psychodynamic-, cognitive-, behavioral-and counseling-based approaches. Many studies have shown that EMDR is effective in reducing stress symptoms after trauma. In the present study, we discussed single session EMDR intervention in a patient presented with symptoms of posttraumatic stress symptoms after sexual harassment. A 15-year-old female was first referred to The Center of Prevention and Research for Child Neglect and Abuse because of a forensic event. In the interview it was found out that she became more ashamed; avoided from people around her; had nightmares; and became a low-spirited person after the event. After completing reporting procedures related to forensic event, the treatment for Posttraumatic Stress Disorder was initiated in our outpatient clinic, which was consisted of 50 mg sertraline. During follow-up visits, it was observed that there was a partial improvement in her symptoms. The patient reported that there was an improvement in her good spirit and anxiety but it was found out that the symptoms such as checking back behavior when she is outside, crying upon remembering the event, distrusting to anybody, being startled and jumping were persisting. The therapeutic interviews were maintained by escalating sertraline dose to 100 mg/day. No improvement was observed in symptoms despite increased sertraline dose. Thus, the patient was informed about EMDR therapy. The patient gave consent for the therapy and one session of EMDR therapy was applied. Another interview was performed one week after the session. In the interview, the patient reported that there was a marked improvement in her symptoms and anxiety and she stopped to blame herself and became more social. It was also observed that the patient was doing well after discontinuation of drug therapy. The visits were withdrawn when the patient reported that she had no problem. According to EMDR approach, memories about traumatic experience are inappropriately stored in the memory. The memories stored in this manner cause non-functional responses. EMDR leads to re-processing of traumatic experiences, which were stored with their original image, thought and perception without processing. By EMDR, desensitization occurs for the input causing stress and appropriate attitudes and skills are provided to express a better functioning. In the present case, EMDR provided the establishment of new cognitions, and a new and positive self-confidence causing better functioning of the patients by re-processing negative perception, image and cognitions. We presented this case to emphasize the benefit of EMDR and the field requiring further studies.