In this study, a new hierarchical decision-making and decision-fusion mechanism is introduced for solving decision making problems in a consistent manner. This mechanism is constructed by using a genetic algorithm. The proposed mechanism employs fuzzy logic and a performance index determined based on the performance of decision-making agents at successive hierarchical levels. The mechanism is such that the decisions in previous levels are influential on the current level decisions according to the performance index introduced. This mechanism is tested on an artificial problem, namely finding the amount of faults in a four tank water system. Copyright © 2007 International Federation of Automatic Control All Rights Reserved.