We provide a comprehensive review of the growth of multinational enterprises (MNEs) based on a quarter-century (25 years) of scholarly international business publications. We synthesize research insights on the determinants of the growth of MNEs through the lens of Penrose’s theory of firm growth, which is the most influential theoretical perspective on firm growth. The review takes stock of the research findings on the facilitators, constraints, and the trajectory of growth of MNEs, and elaborates on the commonalities and differences between research on the growth of MNEs that draws on Penrose’s theory and research that does not. This comparison highlights the opportunity to build an internally coherent theory of the growth of MNEs, that is, a theory that connects ‘what an MNE is’ to ‘what determines an MNE’s growth.’ It also indicates that past research placed a strong emphasis on exogenous factors (e.g., cross-country distances) as key constraints on growth even though the Penrosean lens suggests a close consideration of endogenous factors that drive international growth, as well as endogenizing the ostensibly exogenous growth determinants. The review highlights the importance of firm-specific managerial knowledge and learning, which shapes the direction of the growth of MNEs and ensures its administrative coherence.