The purpose of this paper is to understand how transfer pricing law affects transfer pricing decision making in foreign direct investment enterprises in Vietnam. The study also suggests further research on the determinants over transfer pricing decision making of these enterprises to have better solutions to deal with transfer mispricing in Vietnam. A quantitative research method involving self-administered closed ended questionnaires is extended to manage Directors/Chief Executive Officers, Tax Managers/ Directors, Chief Finance Officers or Heads of Finance from foreign direct investment enterprises in Vietnam. Findings indicate a strong probability of a relationship between transfer pricing law and the transfer pricing decision making of foreign direct investment enterprises in Vietnam. Therefore, there is a need for government to have specific law on transfer pricing. Good transfer pricing database is al-so expected; punishment should be reasonable; transfer pricing audit process should be stronger; transfer pricing trainings should be introduced more to the enterprises. It is be-lieved that the implementation of suitable transfer pricing law in Vietnam will assist the government better deal with transfer pricing abuse in foreign direct investment enterprises. The findings support Vietnamese policy makers to improve the law on transfer pricing. Nevertheless, tax officials and accounting representatives can have indepth knowledge with regard to transfer pricing decision making which the outcome of this study aspires as guidance for better understanding the aspects of transfer pricing decision making while doing business in Vietnam.