The purpose of this study was to examine the instructional effect of problem-based learning on creative problem-solving skills and academic achievement in elementary science classes. Based on the literature review, six stages for problem-based learning were applied: Orientation, Presenting problems and the process of learning, preliminary problem solving, problem solving, sharing results, and wrapping up/evaluating. The subjects were 74 students in two six-grade classes in Gyeonggi province. As a result, the following findings were given: First, the students who were engaged in problem-based learning showed better progress in creative problem-solving skills. Second, science academic achievement of experimental group were better than traditional group. Educational implications were discussed.