This study provides insight into the inconsistent findings on the impact of task complexity on performance by identifying the mediating role of task motivation in the effect of task complexity on DSS motivation and the interactive impact of DSS motivation and DSS use on performance. A research model is proposed to test the mediating and interaction hypotheses. One hundred participants use an experimental DSS application designed for the purpose of this study to complete a rating and selection task. Participants are randomly assigned to a high or low task motivation condition and a high or low task complexity condition. The DSS measures incorporates the accurate additive difference compensatory decision strategy, cognitive effort associated with use of this effortful strategy is attenuated. The partial mediating effect suggests that enhanced task motivation explains the positive effect of task complexity on DSS motivation. In addition, the results reveal that increased DSS use and enhanced DSS motivation lead to improved performance. The results have important implications for DSS research and practice.