Both formative assessment and growth mindset scholars aim to understand how to enhance achievement. While research on formative assessment focuses on external teaching practices, work on growth mindset emphasises internal psychological processes. This study examined the interplay between three formative assessment strategies (i.e. sharing learning progressions, providing feedback, and instructional adjustments) and growth mindset in predicting reading achievement using the PISA2018 data. We focused specifically on samples from the West (the United States, the United Kingdom, Ireland, Canada, Australia, and New Zealand) and the East (Mainland China, Hong Kong SAR, Macau SAR, Chinese Taipei, Japan and Korea) which comprised of 109,204 15-year old students. The results showed that formative assessment strategies were positively, albeit weakly, related to a growth mindset in the East, but not in the West. In contrast, growth mindset was positively related to reading achievement only in the West, but not in the East. The impacts of different formative assessment strategies on reading achievement demonstrated cross-cultural variability, but the strongest positive predictor was instructional adjustments. These findings highlight the potential synergy between formative assessment and growth mindset in enhancing academic achievement as well as the importance of cultural contexts in understanding their roles in student learning.