What is known on the subject?: Reminiscence therapy is a common psychosocial intervention in mental health nursing.Numerous secondary studies have explored the effects of reminiscence therapy interventions in older adults, and while the effects are significant, conflicting results remain. What this paper adds to existing knowledge?: To date, research on reminiscence therapy has examined different disorders in isolation from one another.By illustrating the evidence gaps between studies, this paper highlights the need for a new evidence‐based summary overview of reminiscence therapy research.The results suggest that reminiscence therapy can be beneficial to the improvement of mental health and quality of life for older people.However, we found that the secondary studies were not of high quality and that further high‐quality literature supporting the evidence is still needed. What are the implication for practice?: Reminiscence therapy may be considered a useful non‐pharmacological intervention for older people with mental and psychological problems.However, there is a lack of normative guidelines for reminiscence therapy in terms of intervention time, frequency, and form.The development of a global standard protocol for the application of reminiscence therapy may be necessary for future randomized controlled trials (RCTs). Introduction: Reminiscence therapy is an alternative to pharmaceutical intervention provided during long‐term care, especially for older people with mental and psychological problems. However, the effects of reminiscence therapy remain inconclusive. Aim: The present study aimed to systematically identify, synthesize and describe the research evidence and quality of systematic reviews (SRs) related to reminiscence interventions for older people through an evidence‐mapping approach. Methods: Commonly used English and Chinese databases, including PubMed, EMBASE, The Cochrane Library, Web of Science, CNKI, WANFANG, VIP and SinoMed, were searched from inception till 31 March 2022. The study type was restricted to SRs with or without meta‐analysis. The methodological quality of the included SRs was assessed by A Measurement Tool to Assess Systematic Reviews (AMSTAR‐2). The Microsoft Excel 2019 tool was used for data extraction and coding, and bubble charts were used to synthesize information on the study population, intervention category, original study sample size and classification of findings. Results: A total of 28 SRs were enrolled, including 514 original studies, 91.4% of which were randomized controlled trials. The main participants of the study were depressed older people (7 publications), older people with dementia (10 publications) and ordinary older people (8 publications). The findings of 26 (92.8%) publications were categorized as either "beneficial" or "potentially beneficial." The primary outcome indicators of the effectiveness of the reminiscence intervention for older people are mental and psychological problems (especially depressive symptoms and cognitive functioning), quality of life and categories of positive psychology (e.g., life satisfaction, happiness and self‐esteem). The main factors influencing the intervention effect were the intervention period, residential setting, intervention format (group/individual) and intervention intensity. The intervention settings/contexts were mainly community and long‐term care facilities. However, the methodological quality of 27 (96.4%) of the SRs was scored as either "Low" or "Critically Low." Discussion: Reminiscence therapy has been used to study the mental health and quality of life of older people in various conditions, with significant results. However, due to the limited evidence included in the studies and the low methodological quality, there is still a need to focus on the issue of effectiveness and evidence gaps for different interventions in the field of recall in the future, in addition to efforts to improve the methodological quality and standardize the reporting process for the evaluation of reminiscence intervention systems. Implications for Practice: Reminiscence therapy may be considered a useful non‐pharmacological intervention for older people with mental and psychological problems. A standard protocol for reminiscence therapy may be necessary for future studies. [ABSTRACT FROM AUTHOR]