Teachers' instructional practices surrounding written assignments have been little researched, despite writing remaining the primary means of assessment in higher education, including postgraduate professional development programmes. In this paper, we report a study that explored what a sample of lecturers in a Master of Education programme at an English-medium university in Hong Kong did to support students' assignment writing. We integrate perspectives provided by the relevant higher education literature, the academic literacies approach and North American rhetorical genre studies to shed light on the findings derived from our analyses of interview and documentary data. We showed that our lecturer participants both engaged in direct instruction on assignment writing and provided indirect support. Our study contributed to the existing literature and raised questions for future research.