Mental health disorders have a disproportionately large impact and burden in low and middle-income countries (LMICs). The poor physical health suffered by people with serious mental illnesses (SMI) is a growing area of study as researchers attempt to uncover the root reasons and develop effective interventions. Patients with SMI experience extra difficulties while obtaining dental care, including poor collaboration and communication with dental practitioners, and economic pressures. This scoping review aims to fill in the gaps in our understanding of primary prevention strategies for oral health issues in SMI patients by mapping the available literature on the topic. The primary goal of this research is to identify oral health interventions for SMI patients in the literature that can assist SMI patients and avoid costly dental treatments.