Family businesses play an important economic role worldwide. Their performance is of particular interest to researchers because of their resilience. This performance can be influenced by the family's involvement in the business. This involvement may be in the management of the company, in its shareholding or in both simultaneously. Based on this observation, the aim of this book is to measure the influence of each level of family involvement according to different performance indicators. Following a literature review aimed at establishing a theoretical basis for the concepts of family business, governance and performance, a quantitative study was carried out on a sample of 260 Belgian and Luxembourg SMEs (both family-owned and not). The results showed that family management leads to better performance, but not that companies managed and controlled simultaneously by the family are more successful. This book contains results and practical implications that may be useful to managers and owners of family businesses.