Abstract Decision making is one of the most important and frequent tasks among managers and employees in an organization. Knowledge about more stable cognitive characteristics underlying decision making styles has been requested. This study aimed to examine the relationship between rational decision making style, cognitive style, self efficacy and locus of control. Possible interaction effects in relation to gender were also analyzed. 186 employees at the Ministry of Defence were surveyed. Cognitive style, self efficacy and locus of control were significantly predicting rational decision making style. There was no interaction effect by gender found in this study. An individuals` approach and thinking practice when facing situations that require decision making, is of practical importance in relation to selection and placement, communication, counseling, team building, training and development.