BACKGROUND: Posttraumatic stress disorder is a mental health condition outlining psychological sequelae experienced after encountering a traumatic event. Complex posttraumatic stress disorder, however, is increasingly recognized as being distinct from posttraumatic stress disorder. This is due to an observed variation from what is traditionally defined as a traumatic event, as well as greater heterogeneity in its presentation. Cultural factors may also influence definitions of traumatic events and heterogeneity in presentation. CASE PRESENTATION: In this case, a 27-year-old Malay male presented with a 9-year history of obsessive-compulsive symptoms of predominantly sexual content. Although initially treated as obsessive-compulsive disorder, persistent negative self-image and features of complex posttraumatic stress disorder surfaced in the course of therapy, stemming from a culturally-related punitive upbringing as well as bullying by peers. He responded markedly well to trauma-based psychotherapy and remains well at time of writing. CONCLUSION: A diagnosis of complex posttraumatic stress disorder should be considered in the individual who presents with mental health difficulties, particularly if the individual's symptoms are atypical to classical diagnostic criteria or the individual does not respond to conventional treatment. It is important to note the role of cultural background-this may give rise to unique presentations of complex posttraumatic stress disorder, and the triggering events may not be traditionally defined as traumatic. Cultural background may also potentially inform treatment and future prevention strategies for complex posttraumatic stress disorder.