The paper is based on the results of a study of secondary school principal decision-making styles conducted in eight regions of the Russian Federation (one per federal district) in 2014 using the methodological approach developed by Alan J. Rowe. The study aimed to assess the reformist potential of Russian school principals. We believe that this potential is determined in the present context by a leadership style that involves teachers in decision-making processes and the delegation of responsibilities to them in uncertain situations that require them to solve extremely complex tasks. Using the two-factor leadership model proposed by B. Bass, we suggest that either the transformational or transactional leadership style may prove to be effective depending on a given school's individual circumstances. Consequently, two types of leaders may be the most effective in terms of their ability to enact reforms: (1) principals who mainly exhibit a conceptual decision-making style and secondarily make recourse to an analytical style; (2) principals who mainly exhibit an analytical decision-making style and secondarily make resource to a conceptual style. The article establishes that only 12% of school principals apply the conceptual decision-making style while relying on an analytical style to a secondary degree. These are the principals who we classify as transformational leaders. Only 11% are effectively prepared to implement changes given a specific environment. These are the transactional leaders who are likely to change their leadership style for a transformational one. [This article was translated by Kenneth Cargill.]