This study investigates how scaffolding type and learners' epistemological beliefs influence ill-structured problem solving. The independent variables in this study include the type of scaffolding (task-supported, self-monitoring) and the student's epistemological belief level (more advanced, less advanced). The dependent variables include three components of problem-solving skill (problem representation, solution development, monitoring and evaluation). The two-way multivariate analysis of variance results reveal that students in the self-monitoring scaffolding group earned higher scores on problem representation and solution development than those in the task-supported scaffolding group. Students with more advanced epistemological beliefs also earned higher scores on solution development and monitoring and evaluation than did those with less advanced epistemological beliefs. In addition, a significant interaction was found between scaffolding type and epistemological belief level. These findings suggest that students can benefit from self-monitoring scaffolding in web-based problem solving and that different types of scaffolding should be provided according to the student's epistemological belief level.