The structure of the Italian industry is characterized by the prevailing of small sized companies and the presence of very few large companies. For a long time a shared conviction was diffused among scholars and practitioners that the strength and the safety of Italian industry were based on the industrial districts, i.e. a system of interdependent and co-localized small companies deriving their competitive power from an effective and efficient division of labor. This book stresses the idea that the new, vital and promising phenomenon for the competitiveness of the Italian industry is now that centered on the mid-sized companies and on the system of their interconnected firms that represent a constituent part of their business model. Mid-sized companies, frequently emerging from the context of an industrial district, that have grown and developed internationally thanks to an original business model that combines the advantages of both the large and the small size. These companies do represent a strong entrepreneurial force that accompanies the district force that has characterized and made famous the Italian industry worldwide. The book analyzes the business models and the strategies implemented by a number of Italian successful mid-sized companies that have registered very high growth rate in the period 2006-2008 and had then to face the dramatic changes of the economic and competitive context. A quantitative and qualitative analysis of the phenomenon of the mid-sized companies is reported in the book with consequences in terms of management and industrial policies. The book is structured in three parts: the first part introduces the debate existing in literature on the role of the mid-sized companies, setting the basis for the guidelines and the interpretative framework developed in the book. The second part gives a quantitative interpretation of the phenomenon, analyzing the Italian mid-sized companies according to their competitive and financial performances. The third part of the book deeps into the details of the business models of 23 mid-sized companies focalizing on their: trajectories of growth; competitive and innovation strategies; inter-organizational network, international strategies and positioning.