This document provides a classroom assessment manual for primary and secondary school teachers in Ethiopia. It was prepared by Arega Mamaru of the National Educational Assessment and Examinations Agency, with support from the Russia Education Aid for Development Trust Fund. The manual aims to help teachers effectively implement competency-based assessment aligned with Ethiopia's reformed competency-based curriculum. It covers topics such as the purpose and principles of classroom assessment, formative and summative assessment strategies, constructing and using various assessment tools, analyzing assessment results, and ensuring assessment improves teaching and learning. The development of this manual addresses a need for clear guidance on classroom assessment to enhance educational quality and student learning outcomes in Ethiopian schools.