The concept of “Assessment-of-Learning” (AoL) has long been the tradition in most school assessment practices in Hong Kong. In view of the deficiencies in the assessment mechanism, the Education Commission (2000) recommended “Assessment-for-Learning” (AfL) as one of the major areas of action in the current education reform. This paper reports the outcomes of a research study designed to investigate the practice of assessment for learning by Hong Kong teachers. The project was a collaborative one, involving the School Development and Evaluation Team (SDET) of the Chinese University of Hong Kong and teachers from 20 kindergartens. In the project, central seminars, workshops and meetings were provided to the participating schools for the purpose of enhancing teachers’ Assessment for Learning (A fL) competency in their daily teaching. A questionnaire of 60 items was administered twice to teachers from the participating kindergartens at the beginning as well as towards the end of the project in order to assess their uses of the nine AfL strategies, namely, informing teaching objectives, informing success criteria, effective questioning, quality feedback, self-assessment, peer assessment, collecting learning evidence and teacher reflections in their daily teaching. Results indicate that there is a remarkable improvement regarding teachers’ habits in utilizing AfL strategies after the intervention. This research has pioneered a quantitative study of the practice of AfL in kindergartens and has validated an instrument for assessing such a practice. The framework, the instrument, the findings and insights generated from the study may have significant contributions to the improvement of classroom teaching in kindergartens. Copyright © 2014 ICSEI.