Studies of Japan’s ascent to great power status in the early twentieth century typically recognize the dual roles of industrialization and militarization. However, few scholars identify the role played by large, family-owned conglomerates known as zaibatsu. I analyze the nature and structure of these firms and how their business strategies, capital accumulations and organizational structure impacted their development. These features of zaibatsu are used as lens to identify their specific impact on Japanese industrialization during the Meiji period. I use research from historians, economists and zaibatsu corporate records to complete my analysis. I argue that characteristics associated with zaibatsu were instrumental in the nature and speed of Japanese industrialization and were responsible for Japan’s ascent to great power status by 1922, as represented by the Washington Naval Treaty.