In recent years, it has become apparent that knowledge is a critical component of creative thought. One form of knowledge that might be particularly important to creative thought relies on the mental models people employ to understand novel, ill-defined problems. In this study, undergraduates were given training in the use of causal relationships in applying mental models in creative problem-solving. A pre-post design was used to assess the effects of this training on mental models and creative problem-solving. It was found that causal analysis training resulted in the acquisition of better mental models (in terms of subjective and objective attributes) and better solutions (in terms of quality, originality, and elegance) to problems calling for creative thought among high-ability participants. The implications of these findings for understanding the role of mental models in creative problem-solving are discussed.