Although the possible link between betrayal and mental contamination (MC) in the context of ObsessiveCompulsive Disorder (OCD) has been the focus of important and innovative theoretical work, the actual findings appear somewhat contradictory. The present narrative systematic review aimed pull together and synthesise research focussed on the relationship between betrayal and MC in OCD and whether the current empirical literature indicates whether or not betrayal could be implicated in the experience of MC in OCD. Experimental and exploratory research studies of both quantitative and qualitative nature were included if they examined factors associated with MC and betrayal in OCD. Ovid and Open Athens databases including PsycINFO, Pubmed, Medline and Google Scholar were searched in May 2023. Quality and risk of bias was assessed using the Mixed Methods Appraisal Tool (MMAT). A total of 16 studies were included in the review (three qualitative, seven experimental, three quantitative non-randomised, two quantitative descriptive and two mixed methods studies). Overall, the current evidence provides some support for a connection between betrayal, MC and OCD in clinical samples with the evidence being more mixed in analogue samples. Strengths, limitations, implications and future directions are discussed.