This study examined the immediate and long-term effects of an Assessment for Learning intervention on pre-service sports coaches’ attitudes towards Assessment for Learning in sports. The hypothesis that the intervention had an immediate effect on the experimental group towards Assessment for Learning was only partially supported by this research. Nevertheless, the hypothesis that the intervention had a long-term effect was supported. This study has successfully shown that the intervention can be very effective in developing competencies in Assessment for Learning among pre-service sports coaches in Hong Kong. Through the intervention, the pre-service sport coaches made positive changes in attitudes towards Assessment for Learning, as used in sports teaching, and recognised its effect on student learning. Their positive responses serve as a “green light” for introducing Assessment for Learning for all in-service sports coaches and physical education teachers in Hong Kong.[Copyright © 2013 Springer Science+Business Media Dordrecht.]