This article scrutinizes the professional support provided to teachers by supervisors to improve the teaching-learning process within the dimensions of learning behaviours and learning assessment in Ethiopian primary schools. The study employs a mixed-methods research design. The questionnaires were responded to by 382 in-service postgraduate diploma primary school principals and supervisors in the Educational Leadership and Management Department at Hawassa University. A semi-structured interview was conducted with 12 senior principals and supervisors. The results illustrate critical gaps in the supervision support to teachers for the improvement of learning behaviours and learning assessment. The study suggests that support-oriented supervision could play a significant role in assisting and improving the teaching and learning process. Hence, regional and federal governments should work together with development partners to enhance the competency of supervisory staff to provide enabling support to teachers and thus improve the quality of the teaching and learning processes in Ethiopian schools.