BackgroundMost of patients with dementia are cared for by family members. Caring for people with dementia is challenging; approximately 30–55% of caregivers suffered from anxiety or depressive symptoms. A range of studies have shown that psychosocial interventions are effective and can improve caregivers’ quality of life, reduce their care burden, and ease their anxiety or depressive symptoms. However, information on the acceptability of these interventions, despite being crucial, is under-reported.MethodsSystematic searches of databases were conducted for literature published on EMBASE, PubMed, The Cochrane Library, Web of Science, and PsycARTICLES until August 2017 and the searches were updated on June 2018. The selection criteria included primary studies with data about the acceptability of psychosocial interventions for informal caregivers and publications written in English. Two authors independently selected studies, extracted study characteristics and data, assessed the methodological quality of the included studies by using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool and Critical Appraisal Skills Programme (CASP) Qualitative Research Checklist, and conducted a narrative synthesis of quantitative and qualitative data.ResultsA total of 10,610 abstracts were identified through systematic searches. Based on screening titles and abstracts, 207 papers were identified that met the criteria for full paper review, with 42 papers from 13 different countries meeting the inclusion criteria. We found high- and moderate-quality evidence showing psychosocial interventions were acceptable, with important benefits for caregivers. Facilitators of acceptability included caregivers’ need for intervention, appropriate content and organization of the intervention, and knowledge and professionalism of the staff. Barriers to acceptability included participants’ poor health status and low education levels, caregiving burden, change of intervention implementers, and poor system performance of interventions.ConclusionThere is preliminary evidence to support the acceptability of psychosocial interventions for dementia caregivers. However, the available supporting evidence is limited, and there is currently no adequate information from these studies indicating that the acceptability has received enough attention from researchers. More well-designed studies assessing psychosocial interventions are needed to give specific statements about acceptability, and the measure of acceptability with psychosocial interventions should be more comprehensive.Electronic supplementary materialThe online version of this article (10.1186/s12888-018-1976-4) contains supplementary material, which is available to authorized users.