The effects of information quality and the importance of information have been reported in the Information Systems literature. However, little has been learned about the impact of data quality (DQ) on decision performance. Representational DQ means that data must be interpretable, easy to understand, and represented concisely and consistently. This study explores the effects of representational DQ and task complexity on decision performance by conducting a laboratory experiment. Based on two levels of representational DQ and two levels of task complexity, this study had a 2 x 2 factorial design. The dependent variables were problem-solving accuracy and time. The results demonstrated that the effects of representational DQ on decision performance were significant. The findings suggest that decision makers can expect to improve their decision performance by enhancing representational DQ. This research extends a body of research examining the effects of factors that can be tied to human decision-making performance.