Many aspects of the problem-based learning cycle aim at stimulating students to elaborate on their knowledge. This elaborative process is considered to be one of the most effective study aids for learning and applying information. One of the opportunities to stimulate this elaboration process is by offering students more, and more diverse, learning resources. Under laboratory conditions, increasing the richness and diversity of the learning materials has often been shown to support students in learning, remembering and applying information. In this study, a curricular perspective was adopted on the question whether students would benefit from more learning resources. Mean study times and achievement scores for 28 problem-based courses were calculated and included in the analyses. Independent variables in both analyses were the number of primary learning resources (i.e., resources students were recommended to study) and the number of supplementary resources (i.e., related, but non-essential resources). Results showed a significant increase in achievement scores for courses with more primary learning resources, but the effect of supplementary resources was limited.