The accounting profession has faced numerous scandals in recent years, which has affected the moral character of accountants. Many decision makings of accountants and managers are influenced by their personal moral values.meanwhile Tax evasion as an immoral phenomenon is one of the concerns of the accounting community.This study aimed to investigate the relationship between two main characteristics of personal moral philosophy- idealism and relativism- with the attitude to tax evasion. For data collection, the Ethics Position Questionnaire of Forsyth (1980) and McGee and Noronha questionnaire of tax evasion (2008) were used. 193 of each questionnaire were collected in Tehran during 2016. Two statistical software, SPSS and EXCEL, were used to test the hypotheses. Kolmogorov-Smirnov test was used to assess the normal distribution of data and T test, correlation and analysis of variance (ANOVA) were used due to the normal distribution of data. The results showed that there is a significant positive relationship between relativism and attitude to tax evasion but there is no significant relationship between idealism and attitude to tax evasion. Also, Control variables included Level of Education, gender and type of employment (private or government)  have no impact on attitudes to tax evasion.