The interpersonal emotion regulation of principals has rarely been examined as an independent issue, although it has been widely recognized that educational leadership is an emotional endeavour situated in an interpersonal context. This study aimed to understand how kindergarten principals engage in interpersonal emotion regulation by examining their strategy use. A case study approach was used to collected data, and a thematic coding analysis was conducted to generalize the specific strategies adopted by 12 kindergarten principals from Hong Kong. The findings showed that the principals mainly used four types of strategies to regulate the emotions of self and others, namely, intrinsic emotion-improving, extrinsic emotion-improving, extrinsic emotion-worsening, and extrinsic emotion-suspending. Comparatively, emotion-improving strategies for both intrinsic and extrinsic regulation are the preferred choices of these kindergarten principals. This study identified a new category of interpersonal emotion regulation strategies for kindergarten principals, namely, extrinsic emotion-suspending which has rarely been examined in the literature. With these findings, this study offers fresh insights into kindergarten principals' emotion regulation and leadership practices and extends the understanding of the role of emotions in educational leadership.