This study extends our knowledge of leadership development, specifically Master's in Business Administration (MBA) programs, from a gender perspective. It presents a comprehensive case, women-only development program and conducts an empirical, longitudinal, qualitative study of the effect of one of the program modules, namely, the women-only MBA, on the women's career success. The empirical study focused on self-efficacy mechanisms for explaining the women's appraisals of their changes in abilities affecting their career success during the MBA program. The participants were interviewed twice: once at the beginning of the MBA and then after completing it. A trusting atmosphere, social support, new business competencies, and the participants' ability to re-frame their mindsets concerning women's career potential were detected as significant sources of self-efficacy gained from the MBA. Encouragement from significant others, typically respected males, was also found to be a promoting factor.