The main aim of this study was to investigate and discover whether going through the process of reflection by keeping reflective design journals (RDJ) enhances architecture students' metacognition and whether this enhanced metacognition improves their design understandings and skills. The study was a mixed-methods design and utilised content analysis method to identify the metacognitive actions of the participants. The study also investigated participants' attitudes towards RDJs and their views regarding the effect of enhanced metacognition on their design understandings and skills. Twenty college students registered to an undergraduate course offered by the department of Architecture participated in the research. The findings of the study revealed that by writing in their RDJs, participants were able to progressively enhance their metacognitive skills and performed several metacognitive actions by using the four main metacognitive strategies: awareness, organisation and planning, monitoring, and evaluation. The results also disclosed that participants found RDJ keeping exceptionally effective and stated that their enhanced metacognition improved their design understanding and abilities.