The impact of problem-based learning (PBL) in improving academic achievement comparedwith other forms of teaching is equivocal. This paper argues that poor tutorial preparation and vague reporting of the brainstorming stage of PBL are major contributing factors. To address these issues this study incorporated a scaffolding mechanism into the pre-tutorial brainstorming stage of the PBL process based on de Bono's (1995) Six ThinkingHats. Results confirmed that pre-tutorial preparation, when measured by attendance and academic achievement, increased across all levels of the undergraduate program for the PBL groups that used scaffolding, when compared to PBL groups without scaffolding and lecture-based delivery groups. This study supports the inclusion of scaffolding during the brainstorming stage of PBL.