Sport has become a highly valuable “product” that is typically commercialized via sports events. Diverse types of income generated from sports events, especially from the international ones, raise stimulating income tax issues. These issues constitute the subject of the Thesis, which is divided into two main parts: (I) income deriving from an international sports event and (II) taxation of the income concerned. The main purpose of the first Part is to identify the main income sources, of both individuals and enterprises, which may derive from an international sports event. The second Part relates to the taxation modalities mainly based on the OECD Model of the income sources identified in the Part I. The analysis made throughout the Thesis demonstrates the uncertainty prevailing in this particular area of international tax law. As a remedy, the adoption of “International Sports Events Tax Exemptions Acts”, “International Sports Events Taxation Acts” and/or detailed general explanatory reports on the relevant tax law rules (all on a domestic law level) is suggested.