Background: The prevalence of falls involving people with intellectual disabilities (ID) is high in comparison with the general population. There has been little evidence to date on the contributing risk factors. The objective of this review was to identify risk factors for people with intellectual disabilities. Method: Literature searches were conducted using electronic databases to explore evidence on the subject, and narrative synthesis was employed to analyse the results. Results: Seven risk factors were identified: decreasing physical ability, epilepsy, paretic conditions, impulsiveness, previous falls, incontinence and non-use of assistive equipment. Thematic analysis identified factors across the four concepts: the person, the situation, ongoing and protective factors. Conclusion: Factors for falls involving people with intellectual disabilities are dynamic and multifactorial. Some are specific to the population; however, further research is required to develop the understanding of the possible reasons. The findings have implications across policy, education, practice and research.