Permanent establishment is a standard for distribution of taxing rights over business profits of a foreign enterprise in international taxation context. As dated to 10/8/2016, Vietnam has concluded Double Taxation Agreements with 76 countries and territories which contained the permanent establishment under Article 5. In order to assist relevant countries in drafting double tax treaties, the OECD and the United Nations (UN) have contributedly released Model of Tax Conventions (the Models) which also included the permanent establishment article therein. Additionally, both OECD and UN have individually published the Commentaries of the Model Tax Conventions which have been accepted as international customary law for interpretation of tax treaties. This study aims to analyze several existing forms of permanent establishment under Vietnam Double Tax Agreements and Circular 205/2013/TT-BTC of the Ministry of Finance as the implementing guidance for these treaties. Further, the study explored different approaches of Vietnam Double Taxation Agreements in comparison to the Model Tax Conventions of OECD and UN in respect of permanent establishment existing forms. The results showed that Vietnam DTAs substantially supported the UN Model rather than the OECD Model. Moreover, a number of recommendations were proposed for amending and modifying the Circular 205/2013/TT-BTC to catch up with modern businesses.