This study focuses on multinational corporations (MNCs) and their role in chemical nonproliferation. It seeks to understand the influence of MNCs on government commitment and implementation of chemical nonproliferation. Today, globalization of production has changed the landscape of economic and political calculation of states. The economic interdependency between nations raises the saliency of powerful multinational corporations. They are no longer bounded by borders. Instead, technology/product transfers within and between MNCs to them become powerful players in regional and local economies. Studies have traditionally focused the discussion of nonproliferation on national and international levels. The analysis of state implementation mostly hinges on political will, state capability and the characteristics of the regime itself (legal, enforcement etc.). Companies are frequently perceived as the passive target of nonproliferation policies. Yet, few studies examine the aggregated impacts of MNCs on nonproliferation and understand the implication for the future development of international nonproliferation regime. Drawing upon theories from multiple disciplines including international relations, economics, business management, and organizational behavior, I approach the issue of nonproliferation from the bottom up. I argue that MNCs can play a positive role in improving countries chemical nonproliferation commitment. I employ both quantitative and qualitative methodologies to examine the hypothesis. Within the quantitative context, I choose the Chemical Weapon Conventions (CWC) as my case study and adopt both Frequentist and Bayesian statistical approaches to analyze the impact of chemical MNCs on ratification and implementation of CWC. On the qualitative side, I select three countries (Saudi Arabia, China and Germany) and pair each with a leading global chemical MNC (SABIC, SinoChem and BASF respectively). These three case studies provide anecdotal examples of my argument. In combination, these two methodologies offer an innovative approach to the study of international nonproliferation.