With a paradigm shift from a focus on product to one on process in language assessment, assessment for learning (AfL) has been gaining currency in educational policy in different parts of the world. While AfL emphasizes the use of assessment for improving learning and teaching, assessment of learning (AoL) focuses on using assessment for administrative and reporting purposes. In L2 writing, assessment has traditionally been characterized by AoL. Although AfL strategies like process pedagogy, formative feedback, peer response, and conferences have been promoted in L2 writing, these strategies are not widely adopted outside North American educational contexts. In English as a foreign language (EFL) contexts, there is scanty research that investigates writing teachers' attempts to bring innovation to their assessment practices through a focus on AfL. Using data from four Secondary 1 (i.e. Grade 7) classrooms in a Hong Kong school, the study aimed to investigate how the teachers' determination to implement AfL in writing influenced their instructional and assessment practices and impacted on students' attitudes and beliefs regarding writing. Results show that the implementation of AfL resulted in a significant change in teachers' instructional and assessment practices, and students improved their motivation in writing. The paper concludes with a few implications for EFL writing.[Copyright of Innovation in Language Learning and Teaching is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/17501229.2010.502232]