The differential impact of growth language mindsets on second or foreign (L2) writing feedback-seeking behaviour (FSB) is an important yet underexplored area of research. How perspective-taking, a less-researched construct in L2 writing, directly predicts FSB or mediates the paths between growth language mindsets and FSB remains unknown, either. Therefore, the present mixed-method study seeks to explore the impacts of growth language mindsets--specifically related to intelligence, aptitude and age sensitivity--perspective-taking on FSB, and particularly examines whether perspective-taking mediates the relationship between growth language mindsets and FSB. A battery of questionnaires were administered to 571 Chinese learners of English at the tertiary level, of whom six L2 learners were interviewed. Quantitative results showed that growth mindsets on language aptitude and age sensitivity as well as perspective-taking positively predicted both feedback monitoring and feedback inquiry; growth mindsets on language intelligence only predicted feedback inquiry. Perspective-taking mediated the relationship between growth mindsets on language aptitude and both feedback monitoring and feedback inquiry. The qualitative findings highlighted the influences of growth language mindsets and perspective-taking on FSB, with the latter moderated by learning goals and types of writing tasks. This study provides implications for improving L2 learners' growth language mindsets and perspective-taking abilities.