Revision with unchanged content. Mismanagement and miscalculations of the Top Management Team (TMT) are, alongside general economic cycle arguments, the most commonly proposed determinants of firm performance. The composition of the TMT is seen as a crucial variable in shaping organizational outcomes. However, does the composition of the TMT indeed influence the firm performance? If so, then in which ways and to what extent? Does the influence differ for firms operating in dynamically different and various environments? Sabine Kiefer endeavors to explore the topic of TMT diversity and its influence on the firm performance by critically investigating German companies. Building upon previous theories and empirical results, a new - not yet empirically investigated - curvilinear relationship is proposed. Detailed information about the sample, the data gathering process and measurement choices are outlined and the hypothesis is investigated by using regression analysis. This book should appeal to all those interested in TMT research and its implications on the financial outcomes of firms.