The aim of this contribution is to highlight the long-term evolution of family capitalism in Switzerland during the twentieth century. We focus on 22 large companies of the machine, electrotechnical and metallurgy (MEM) sector whose boards of directors and general managers have been identified in five benchmark years across the twentieth century, which allows us to distinguish between family-owned and family-controlled firms. Our results show that family firms prevailed until the 1980s and thus contradict the dominance of 'managerial capitalism'. Although we observe a decline of family capitalism during the last decade of the century, the significant remaining presence of family firms in 2000 allows us to relativise the advent of investor capitalism.