This study reviews and synthesizes empirical research literature focusing on the relationship between boards of directors and organizational effectiveness of U.S. hospitals. The study examines literature published in scholarly journals during the period of 1991-2017. Fifty-one empirical articles were identified that met the study's inclusion criteria. A framework from the corporate governance and nonprofit governance literature is used to classify the articles according to level of analysis (individual actors, governing bodies, organizations, and networks, alliances and multiorganizational initiatives) and focus of research (formal structure and behavioral dynamics-including informal structures and processes). Results are discussed, emerging trends are identified, and recommendations are made for future research.