Objectives Residential and long-term care facilities struggle to support older residents who experience a loss of autonomy, use psychoactive substances and face issues related to their consumption. Substance use can interact negatively with other physical, mental health or social conditions (e.g., homelessness) to create particularly complex profiles. In Quebec, as in many other countries around the world, there are often no clear guidelines for the care of elderly residents using psychoactive substances. The purpose of this study is to document the characteristics of existing interventions and practices towards older people who use psychoactive substances in residential and long-term care facilities in order to support decision makers with improvement of services and quality of care. Methods We carried out a scoping review of the scientific literature. We consulted 7 scientific databases (MEDLINE, EmBASE, PsychINFO, CINAHL, SocIndex, Ageline, Érudit). To identify the relevant grey literature, we explored the websites of governmental, non-governmental organizations and professional associations in the fields of addiction and aging in a selection of OECD countries. In addition, 31 experts were solicited to enhance the documentary research process. We conducted a thematic analysis on 65 documents. Results The philosophies underlying practices related to substance use reflect a hard balance to strike between priorities to be given to health, safety, and respect for human rights in residential and long-term-care settings. These philosophies, and the practices that stem from them, are distributed along a continuum ranging from the demand for abstinence to a total "laissez-faire" approach to substance use. Services offered are varied and involve complementary expertise in the health and social fields to meet the complex needs of this population. Finally, a diversity of organizational dynamics is observed: proposed interventions regarding substance use can be structured programs, informal interventions, internal substance use management policies, or specific settings for older adults who use substances, such as wet eldercare facilities. Conclusion This portrait of the interventions that target the use of psychoactive substances in residential and long-term care settings may assist care workers and service managers in Quebec and internationally, with clinical practice improvements. This may ultimately support both seniors-dedicated and addiction services. In view of population aging and the complex needs of older populations, clear guidelines are crucial to ensure the quality of care and services in these settings.