Women-only leadership development programmes are vital for reducing the global gender gap in senior management; however, research on their impact is limited. This study explores the effect of a transformational women's leadership development programme on self-confidence among female academics in a South African higher education institution. A mixed methods approach combines quantitative analysis to assess the changes in women leaders' communication confidence, while the qualitative analysis explores the women leaders' experiences in adopting new behaviour patterns. The quantitative results reveal significant enhancements in women leaders' confidence, underscoring the programme's ability to drive transformational change. The qualitative insights uncover a four-phase transformational learning process, which includes encountering a disorienting dilemma, meaning-making, achieving transformational insight and integrating these insights into leadership practice.