This study explores the effectiveness of guided reflective journals to improve intelligibility in a Japanese higher educational context. Based on qualitative and quantitative methods, the paper evaluates changes in speech over the duration of one semester. In particular, this study focuses on changes in prosodic features such as stress, intonation and pausing in a small group of 22 students who were studying English at one university in Japan. Segmental features are also considered. Results from this study show that the goal-setting strategies embedded in the reflective journals served to direct autonomous learning efforts and motivated the participants from the experimental group to improve more than the control group, especially with regard to word stress, intonation and pausing. While the participants from the experimental group focused their learning goals mainly on prosodic features, no significant improvements were made in segmental features. While further research is needed in this area, this paper shows that guided reflective journals may be one intervention strategy to support learning and improve the pronunciation skills of EFL learners. However, further research is needed to explore the use and benefits of guided reflective journals as an independent learning tool to improve pronunciation.