This study investigated how competency-based and multi-dimensional assessment approaches contribute to learners’ cognitive, social, and emotional development. A mixed research approach particularly explanatory sequential design was employed. The actual sample size of 300 secondary school students were selected through stratified random sampling. The research addressed three key questions: (1) What types of competency-based and multi-dimensional assessment approaches are currently utilized? (2) To what extent do competency based and multi-dimensional assessment approaches predict learners’ development? and (3) What contextual barriers affect the implementation of competency based and multi-dimensional assessment approaches? Quantitative data were collected using questionnaires. Collected data were analyzed using descriptive statistics, multiple regression, path analysis, and structural equation modeling (SEM). Qualitative data underwent thematic analysis. Descriptive results showed that secondary schools employed a range of assessment approaches, with the most common being formative assessments (64%). In contrast, structured peer and self-evaluation procedures, as well as competency-aligned rubrics, appeared less frequently practiced. Multiple regression analysis showed that competency-based and multi-dimensional assessment approaches significantly predicted holistic learner competencies (F(3, 296) = 18.42, p < .001, R² = .427). Structural equation modeling confirmed strong direct effects of cognitive oriented assessment approach on learners‘ competencies (β = .52). Path analysis revealed that emotional competence partially mediated the influence of assessment approach. The study recommends targeted professional development, improved resource allocation, and strengthened school level support to adopt competency-based and multi-dimensional assessment approaches.