Purpose of Review <p>This article synthesizes recent empirical findings on the relationship between obsessive-compulsive disorder (OCD) and trauma, with a focus on prevalence, clinical presentation, assessment, and treatment implications. We summarize best practices for trauma-informed OCD care, with the important caveat that the literature on assessment, case formulation, and treatment for the comorbid presentation of trauma and OCD is in the beginning stages of development.</p> Recent Findings <p>Prevalence estimates of OCD and comorbid trauma range from 30 to 82% depending on sample and criteria. Co-occurring trauma and/or PTSD can influence the course of OCD, symptom expression, and response to treatment. OCD and trauma presentations may be functionally intertwined or separate entities, which require different approaches to assessment and treatment. A trauma-informed assessment approach requires administration of validated measurement tools for each condition, as well as evaluation of the onset, content, and functional role of obsessions and compulsions in relation to trauma history. Treatment for each condition can be carried out simultaneously or sequentially, depending on the presentation.</p> Summary <p>There are very few existing tools for the assessment of co-occurrence, as well as recommendations for treatment sequencing and delivery. Future research is needed to clarify etiological pathways, validate current assessment strategies, and test treatment approaches to improve outcomes for a complex clinical population.</p>