The growing importance of internationalization and the global dominance of English in higher education mean pressures on expanding English-taught degree programs (ETDPs) in non-English-speaking countries. Strategic considerations are necessary to successfully integrate ETDPs into existing programs and to optimize the effects of internationalization. Previous studies have proposed that innovation theory might explain effectively how to achieve this. This article examines the validity of innovation theory as a framework for understanding the institutionalization of ETDPs and identifies determining factors of successful outcomes. A case study was conducted in Dutch universities to identify factors influencing the institutionalization of ETDPs. A qualitative analysis of 15 interviews with academics demonstrated that an innovation theory-based framework can enable a systematic understanding of the institutionalization of ETDPs and can be effective in analyzing the influencing factors. Analyses utilizing this framework can contribute to strategic planning and policy-making for internationalization at national and institutional levels.