摘要:The purpose of this study is to examine the determinant of tax practitioners ethical decision making behaviour. The factors that were examined in this study were individual factors; PRESOR, Machiavellian , and situational factors; risk preference, importance of tax to practice, exposure to current tax practice, closeness of client relationship. This study used survey method in gathering the data. Population of this study were tax practitioners joined in IKPI (Ikatan Konsultan Pajak Indonesia) in Jawa Timur, Indonesia. A total of 38 samples were processed using Logistic Regression. The model of this study explained 45 % determinants of tax practitioners ethical decision making. The results of this study showed that PRESOR and Machiavellian as individual factors affects tax practitioners ethical decision making. Situational factors in this study, which were risk preference, importance of tax to practice, exposure to current tax practice, closeness of client relationship was proven not to have a significant effect to ethical decision making.