This article explores the effect of computerized scaffolding with different scaffolds (structuring vs. problematizing) on intra-group metacognitive interaction. In this study, we investigate 4 types of intra-group social metacognitive activities; namely ignored, accepted, shared and co-constructed metacognitive activities in 18 triads (6 control groups; no scaffolds and 12 experimental groups; 6 structuring scaffolds and 6 problematizing scaffolds). We found that groups receiving scaffolding showed significantly more intra-group interactions in which the group members co-construct social metacognitive activities. Groups receiving problematizing scaffolds showed significantly less ignored and more co-constructed social metacognitive interaction compared to groups receiving structuring scaffolds. These findings indicate that scaffolding positively influenced the group members' intra-group social metacognitive interaction. We also found a significant relation between students' participation in intra-group social metacognitive interaction and students' metacognitive knowledge. Twelve percent of the variance in students' metacognitive knowledge was explained by their participation in intra-group shared social metacognitive interaction. Therefore, future research should consider how to design scaffolds that elicit intra-group social metacognitive interaction among group members to enhance the development of students' metacognitive knowledge.