This chapter addresses the principle of non-discrimination within international administrative law. It examines how international administrative tribunals distinguish between types of discrimination—direct, indirect, positive, and negative—and outlines the allocation of the burden of proof in these cases. The chapter reviews grounds of discrimination, such as race, gender, nationality and place of residence, age, and disability. The jurisprudence spans a variety of contexts, including recruitment, salaries and financial entitlements, career progression, pension rights, and contract termination. The chapter also analyses the principle of equal pay for equal work, a cornerstone of the prohibition of discrimination, discussing its scope and limits. While many rulings reflect a high standard of scrutiny, some structural forms of discrimination persist within employer organisations, particularly concerning gender. The chapter concludes that, despite advancements, international administrative tribunals continue to play a crucial role in addressing and reducing discrimination through judicial oversight.