Dyadic interventions simultaneously engage both people with dementia (PWD) and their informal caregivers (ICGs). This scoping review study identified the strategies for engaging dyads, described the perceptions of the dyads on these strategies, and reported the attrition rates of the dyadic interventions reported in the literature. Articles published up to July 2020, reporting a PWD-ICG-dyads intervention were searched in PubMed (Medline), PsycInfo, CINAHL, and the SSCI. Backwards citation chasing was conducted. A total of 37 studies were included. Seven engagement strategies were identified, which involved: ensuring a good-quality interventionist; offering take-home supporting materials; establishing peer support among the participants; tailoring the intervention content; conducting the intervention in a convenient location; conducting the intervention in a comfortable physical environment, and using a short and succinct programme. The dyads’ subjective experiences of these strategies were reported. The attrition rates of the included studies were ranged 0% - 59.1%.