The adverse human rights impacts of arms exports to conflict zones are routinely ignored in favour of the security and commercial interests that drive the arms trade. Employing an interdisciplinary approach which incorporates elements from transnational law and virtue ethics, this doctoral thesis argues that arms exports to conflict zones require the implementation of preventive responsibilities which elevate human rights considerations and extend to all key supply-side actors. Chapter One explains the scope of the inquiries. Chapter Two details the essential features of arms exports to conflict zones. Chapter Three illustrates the historical relationship between the arms trade, security and commercial interests. Chapter Four particularises the three-pronged human security-based approach to conceptualising responsibilities. Chapter Five analyses the most significant international and regional arms control instruments adopted since the 1990s and applicable to small arms exports. Chapter Six scrutinizes the domestic export control regimes of the six major exporter states. Chapter Seven examines the brokering regulations for intermediaries, and assesses soft law instruments applicable to arms manufacturers and banks, along with their corporate policies. Chapter Eight develops a conceptual framework for human rights due diligence for the arms sector. Chapter Nine reflects on the continuing practical and conceptual challenges for preventive responsibilities and their potential for transforming arms export practices.