In this paper we explore the role of mindfulness interventions in developing self- and other-oriented compassion among leaders within organizational settings. We draw on a longitudinal study of 62 organizational leaders who participated in an eight-week mindfulness training to examine how mindfulness contributes to the cultivation of a compassionate mindset and leadership practices. The data for analysis, collected at four time-points, comprises pre-intervention assessments and post-intervention interviews (in total 159 interviews), including six- and twelve-month follow-ups. We find mechanisms underpinning co-active compassion, such as interconnectedness, perspective-taking, and mutual support, which manifest at the collective level. Co-active compassion reveals a reciprocal interplay between self-care and the care for others, enhancing both individual and collective compassionate competencies in leadership. This study contributes significantly to both mindfulness and compassion in leadership literatures by showing that mindful self-compassion in leadership is a dynamic, interpersonal phenomenon, crucial for leaders who aim to effectively balance self-care with their responsibility towards others. We also extend current understanding of compassion in leadership by providing empirical evidence of the role of mindfulness in fostering both self- and other-oriented compassion. We discuss theoretical and practical insights for developing compassionate leadership competencies in the face of modern organizational challenges.