AbstractBackgroundComplicated grief has been identified as a phenomenon in the general population, and there is an increasing body of research investigating complicated grief in people with intellectual disability. The aim of this study is to synthesise this existing knowledge from research published between 1999 and 2022.MethodsA structured systematic review using PRISMA guidelines was conducted, which searched three commonly used databases (Medline, PsycINFO and CINAHL) for research on the topic of bereavement and intellectual disability. The articles identified in this search were screened to identify those that addressed the issue of ‘complicated grief’, with all abstracts and subsequent full texts reviewed by two researchers.ResultsIn total, 179 abstracts were initially identified, with 34 articles eligible for full text screening and 18 papers reaching criteria for inclusion. Data relating to the studies' objectives were extracted under the headings of definition, defining principles, signs and symptoms, risk factors and treatments for complicated grief in intellectual disability. Thematic analysis of the extracted data was performed to identify key themes.ConclusionsThis review highlights that people with intellectual disability are likely to experience complicated grief reactions and that complicated grief is both underestimated and a clinically significant condition for people with intellectual disability. Future research should work to clarify diagnostic criteria and identify appropriate interventions.