Assets misappropriation is one of the types of fraud that has the potential anxiety for managers, auditors, and firm’s stakeholders. In spite of strict rules, this phenomenon is increasing how assets misappropriation has the most frequencies in different societies. But based on studies results in the accounting field, there is low paying attention on it. Therefore, the aim of the present study was to investigate the effect of auditors' functional thinking styles on the ability to detect assets misappropriation by emphasizing the mediating role of auditors' professional skepticism.This research is of applied and survey type. The statistical population of the study includes auditors working as members of the Iranian society of certified public accountants in 1400, of which 384 people were selected as the sample size. Research data were collected through a questionnaire and analyzed using structural equation modeling by partial least squares (PLS) approach. Findings show that functional thinking styles (including legal, judicial, and executive styles) have a direct positive effect on the ability to detect asset misappropriation; but the intensity of the effect of executive thinking style (simple information processing) is weaker than the two styles of judicial and legal thinking (complex information processing). also, the positive effect of judgmental and executive thinking styles on the ability to detect the misappropriation of assets with the mediating variable of professional skepticism is significant; But the positive effect of legal thinking style on the ability but the positive effect of legal thinking style on the ability to detect the misappropriation of assets with the mediating variable of professional skepticism is not significant. The study shows that auditors' professional skepticism increases their ability to detect misappropriation of assets.The findings can help auditors to better train auditors at the university and to develop better auditing standards and better performance of audit work and detect fraud.