Abstract This chapter studies the taxation of international partnerships. There are at least three reasons why partnerships are preferred to other legal forms of business (e.g. corporations) in some countries or situations: (1) partnership law is in many countries more flexible than corporation law; (2) partnership law offers in many countries more legal forms to choose from than corporations; and (3) partnerships sometimes offer preferential tax treatment. With respect to the third reason, partnerships are quite often treated as fiscally transparent compared to corporations being separate tax subjects (opaque tax treatment). However, not all states have the same tax treatment for partnerships. Such different tax treatment by states delivers complex tax issues for those partnerships that operate internationally. The chapter discusses the domestic tax treatment of international partnerships before looking at the tax treaty treatment of international partnerships. It also considers the EU law aspects of international partnerships.