The objective of this review is to investigate the relationship between cancer and PTSD, a disease of high prevalence in all and with physical and emotional sequelae. Research on the database PubMed using the terms "Cancer", "Post Traumatic Stress Disorder" and "PTSD" from January 2000 until April 2011. There seems to be a close relationship between the threat caused by the cancer diagnosis and the development of PTSD. Cancer brings negative reactions throughout the treatment on patients, caregivers and familiars, and the prevalence of PTSD ranges from 4% to 9.1% for the full diagnosis, reaching 39% in the presence of partial criteria. The emotional support individual or group emerges as an important factor in reducing the symptoms of PTSD. In this context, the development of measures for PTSD in cancer patients still deserves to be explored in further research, especially in that fit the Brazilian context. The diagnosis of cancer is commonly associated with a traumatic experience and can trigger symptoms of PTSD. Early detection of diagnosis of PTSD in cancer patients, their families and caregivers can be a contributing factor in reducing symptoms and improving quality of life. Thus, parameters and specific measures for this population in relation to PTSD can help develop assessments and educational interventions and psychological measures.