Purpose: This paper aims to explore the best practices to institutionalize the internal quality of student assessment (SA) when a gap emerges between quality conceptualization and practice work, using Imam Abdul Rahman bin Faisal University (IAU) as a case study. Design/methodology/approach: A single-embedded case study research design chronologically presents key events of assuring and improving SA at IAU. It integrates quantitative and qualitative data to provide empirical evidence of changes in SA practices. Findings: Over three years, evident improvements in SA practices resulted in more effective internal quality assurance strategies (e.g., faculty involvement) and the achievement of performance indicators. Research limitations/implications: This study used data from informal observation and self-reports. Thus, it is suggested that future research should use in-depth (e.g. focus group) and diverse data sources from stakeholders (e.g. students) and use emerging global trends to assess SA quality. Practical implications: Involving faculty as changing agents via accountability and training in assuring and improving SA quality leads to measurable improvements. Social implications: A top-down approach alone is insufficient to assure and improve the quality of SA practices, so empowering faculty via involvement and training is inevitable. Originality/value: The quality assurance of SA described in this practice-oriented case places IAU as a leading university in the region, contributes to the external quality assurance of SA, empowers Saudi graduates to compete in the labor market as aspired in Vision 2030 and adds to the literature on quality assurance of SA in a higher education context.