Financial fraud, which occurs in various forms of unethical practices, such as financial corruption, asset misappropriation, and financial reporting fraud, not only damages a company's reputation but also causes irreparable damage to financial markets due to loss of investor confidence. Hence, understanding the causes of these frauds is the key to designing more effective internal controls and creating an ethical organizational culture. Research shows that the occurrence of fraud is contribute to the psychological characteristics of individuals.Thus, the present study aimed to gain a deeper understanding of the mechanism of Machiavellianism, narcissism, psychopathy, and ambition with the fraud intention in accountants and managers. For this purpose, 386 questionnaires were collected cross-sectionally in the summer of 2025 and analyzed through structural equation modeling to test the research hypotheses using AMOS software. The results, while rejecting the direct relationship between narcissism and Machiavellianism with fraud intention and confirming the direct relationship between psychopathy and ambition with fraud intention, show that there is a direct and Significant relationship between narcissism, Machiavellianism and psychopathy with ambition. In addition, ambition mediates the relationship between narcissism, Machiavellianism, and psychopathy with fraud intention.