Though ensuring the fair, reliable, and rapid international sharing of pathogen samples and related benefits is necessary to control infectious disease outbreaks, it has proven difficult. We gathered data from two country cases, influenza sample movements, interviews, and contracts to understand current practices and perceptions. We found that countries shared pathogens for instrumental, political, security, economic and scientific reasons; and that benefits were sought for the global public interest, academic recognition, strengthening national capacities, and economic returns. During outbreaks, barriers arose due to disparities in technology and capacity, biosecurity concerns, commercial interests, and the absence of clear rules. We found consensus on the urgency of improving the global governance of PBS, but not on how to do so. We discuss the options proposed for PBS governance and the need for more focused political leadership to achieve global health security, with equity.