Existing WTO rules overly protect economic interests, often at the expense of sustainable development. To address this issue, I recommend that WTO panels adopt the sustainability test. This test, which I have developed as an academic concept, aims to reconcile WTO law with the UN SDGs. The core of the sustainability test is to balance all elements of sustainable development associated with domestic measures, ensuring that WTO panels’ rulings do not undermine these goals. Balancing different elements associated with legal issues is a common challenge. Judges have developed methodologies for balancing conflicting legal values, known as the balancing approach, especially in the context of constitutional and human rights law. This approach varies across national legal systems and is known as the proportionality test in Germany. Although the balancing approach originated in national law, it is now widely used in international dispute settlements, including those of the WTO. What balancing approach do WTO panels currently take? Can this approach effectively balance different sustainable development interests? If not, what approach should WTO panels adopt when applying the sustainability test? This chapter addresses these critical questions.