This research describes the Private Equity (PE) investment activity within Small and Medium Enterprises (SMEs) in Europe, focusing on Italy and Uniyed Kingdom. SMEs are very relevant for the development of the economy, and it will be analyzed what are the main tools that PE uses to create value and to improve the growth of the companies. After the explanation of the Private Equity activity developments during the last decades and a glance at the modifications that have occurred in this in investment activity, the attention is given to Italian and English deals implemented in the last ten years, looking at the structural and performance changes that occurred at the end of the deals and a short time later. Finally, a multivariate regression has been implemented, analyzing the most relevant contributions to the companies' changes.