In a presentation to the conference on “Security Sector Governance: Defence Production, Sales and Acquisitions” in Kyiv, Ukraine, the author aims to raise the awareness among Ukrainian stakeholders on existing policies, standards, and good practices in corporate ethics of defence companies. The paper outlines key considerations in establishing defence-industrial cooperation across borders and the principles of business ethics. Then it provides examples from the most recent “Company Index” of Transparency International and concludes by emphasising ethical behaviour as a key pre-condition for solid defence industrial cooperation.