This research seeks to understand how family firms design and use management control systems during the professionalization process over time. Professionalization is a process that can involve multiple transitions during which firms can increase nonfamily participation in management and governance and/or formalize control systems. This study adopts a longitudinal case study approach to examine a family firm that was professionalizing to understand the management control system choices made during two transitions of the professionalization process. We contribute to the family business literature by providing a detailed account of how management control systems enable a family firm to transition between forms of professionalization.