This paper evaluates the implementations of assessment and certification in the Ethiopian TVET system based on review of government documents and a descriptive analysis of primary data. The primary data are obtained by administering questionnaires to 184 TVET heads and 547 students/trainees that are drawn from 40 public, private and NGO TVET institutions in Addis Ababa and by administering interviews to 10 key informants. It is found that assessment is being carried out based on regulations/guidelines and assessment tools in accredited assessment centers by accredited assessors. Implementation of the system has directed the effort of stakeholders towards enhancing learners’ competence and has influenced learning. As a result, the number of candidates who passed the assessment in Addis Ababa has increased from 14.3% in 2009/10 to 61.7% in 2015. Findings also point out that the implementation of assessment is to some extent in line with some of the principles (criteria) proposed in the theoretical literature. Encouraging practices are observed in terms of linking assessment with the learning outcomes or competence requirements of work place (i.e., national standards) as well as the authenticity, cognitive complexity, directness, consistency, and transparency of assessment. However, quality of internal assessment is hampered due to gaps in institutional capacity especially among smaller TVET institutions. Furthermore, implementation of external assessment is being affected by challenges such as unethical conduct by some assessors; limited accessibility of assessment as a service; capacity (quality) gaps in terms of assessors, assessment tools, materials and machineries; longstanding (but declining) attitudinal problems disfavoring external assessment; weak linkage between the external assessment system and TVET institutions (i.e., delivery); and, possible adverse effects of competence as a single criteria for renewal of accreditation of TVET institutions/programs. Finally, this paper points out some mechanisms that may help address the implementation challenges of a competence-based assessment system in the Ethiopian context. Key words: evaluation, competence-based education and training, assessment, certification, TVE