Abstract Aims Stigma related to mental disorders is a barrier to quality mental healthcare. This scoping review aimed to synthesise literature on stigma related to mental disorders in Nepal to understand stigma processes. The anthropological concept of ‘what matters most’ to understand culture and stigma was used to frame the literature on explanatory models, manifestations, consequences, structural facilitators and mitigators, and interventions. Methods We conducted a scoping review with screening guided by the Preferred Reporting Items for Systematic Review and Meta-analysis Extension for Scoping Reviews (PRISMA-ScR). A structured search was done using three international databases (PsycINFO, Medline and Web of Science), one Nepali database (NepJol) and cross-referencing for publications from 1 January 2000 through 24 June 2020. The search was repeated to include structural stigma-related terms. Quality of quantitative studies was assessed using the Systematic Assessment of Quality in Observational Research (SAQOR) tool. The review was registered through the Open Science Framework (OSF) (osf.io/u8jhn). Results The searches yielded 57 studies over a 20-year period: 19 quantitative, 19 qualitative, nine mixed methods, five review articles, two ethnographies and three other types of studies. The review identified nine stigma measures used in Nepal, one stigma intervention, and no studies focused on adolescent and child mental health stigma. The findings suggest that ‘what matters most’ in Nepali culture for service users, caregivers, community members and health workers include prestige, productivity, privacy, acceptance, marriage and resources. Cultural values related to ‘what matters most’ are reflected in structural barriers and facilitators including lack of policies, programme planning and resources. Most studies using quantitative tools to assess stigma did not describe cultural adaptation or validation processes, and 15 out of the 18 quantitative studies were ‘low-quality’ on the SAQOR quality rating. The review revealed clear gaps in implementation and evaluation of stigma interventions in Nepal with only one intervention reported, and most stigma measures not culturally adapted for use. Conclusion As stigma processes are complex and interlinked in their influence on ‘what matters most’ and structural barriers and facilitators, more studies are required to understand this complexity and establish effective interventions targeting multiple domains. We suggest that stigma researchers should clarify conceptual models to inform study design and interpretations. There is a need to develop procedures for the systematic cultural adaptation of stigma assessment tools. Research should be conducted to understand the forms and drivers of structural stigma and to expand intervention research to evaluate strategies for stigma reduction.