Traditionally, teachers in Hong Kong schools have used formal tests and examinations to generate summative assessment data for rank ordering students. However, recent education reform, supported by research on science learning, has led to a demand for profound changes in assessment practices, including the adoption of methods novel to many teachers. This paper explores the views of junior secondary science teachers regarding the implementation of alternative assessment tasks in science classes and provides insight into the type and level of support required to facilitate the recommended changes. The findings have implications for the prospects of shifting the current culture of science assessment in Hong Kong and elsewhere. The paper concludes with concrete recommendations for supporting teachers in achieving changes in their assessment practices.[Copyright of Canadian Journal of Science, Mathematics, & Technology Education is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/14926150609556699]