This article is based on a definition of political and civil servant leadership as a behavioral steering style towards the realization of organizational goals. By means of a grounded theory methodology we get some insights in the characteristics and the interaction between both leadership styles in Flemish cities. This two-faced leadership is depicted by means of a tandem metaphor. First, we identify the relevant dimensions to describe the leadership tandem. It becomes apparent that political leadership styles differ greatly both in time and in scope. Civil servant leadership is generally characterized by a weak but presumably growing impact. This combination results in considerable leadership tensions, which is reinforced by several contingency factors: i.e. the influence of the dominant alderman model, the financial situation, the number of staff, the tendency to professionalize, the dominant political and civil servant culture and the structure of central government (e.g. on a Flemish, Belgian and European level).