The globalization, the international trade and the number of multinational enterprises have continued to increase over the last decade. Today over 70 percent of the cross-border transactions take place between related enterprises. The growth of multinational enterprises doing cross-boarder transactions present increasingly complex taxation issues, both for the tax authorities and the companies themselves. International transfer pricing deals with those intra-group transactions where the open market regulator is absent. Transfer pricing has grown to be the most important issue on the tax agenda of multinational enterprises. During the last decades fundamental principles have developed on different levels in the global environment and differences among these guidelines and regulations are of great importance. This theses discuss the divergences of the three big guidelines produced by the OECD, the PATA and the EU, in particular the requirements of documentation, the different methods of arm's length principle and the penalties available. With this background, the Swedish regulation is regarded and examined as well.