The National Certificate of Educational Achievement (NCEA) is the recently introduced national qualification for New Zealand senior secondary school students. Based on a mix of internal and external assessment against achievement standards, it represents a marked change from the previous norm-reference based qualifications. Introduced in 2002, commencing with Level 1, NCEA involved a considerable paradigm shift in assessment practice for teachers. This paper focuses on teachers' perceptions regarding the process of implementing the Level 1 geography NCEA achievement standards. It highlights the initial challenges faced, factors considered to assist and hinder the implementation change process and the lessons learnt.