What makes people behave ethically continues to be at the forefront of business ethics research. The stylistic makeup of the decision‐maker has been suspected to influence individual ethical behavior; however, this body of research accounts only for a handful of studies. This paper investigates the influence of decision‐making styles as an individual difference on unethical behavior, independently from other personal characteristics. Covering a sample of 230 managers, we utilize the preeminent measures of these two constructs in a self‐report survey. Our results suggest that the decision‐making styles of managers do influence their ethical behavior. Whereas managers with a dominant rational or spontaneous style behave ethically, having a more intuitive or avoidant makes them behave less ethically. The results also reveal that with higher levels of education, managers become more unethical. This research conveys important implications for management practice, education, and training.