Widely recognized in the literature as a key to professional development, reflective practice occupies a central place in initial teacher education. In order to develop their reflexivity, students in teacher education programs in the French-speaking part of Belgium are commonly required to write a self-evaluation report after each internship. In this longitudinal study, we evaluated whether the repeated writing of these self-evaluation reports allows students to improve their reflective writing skills in a context where reflective writing is neither taught nor supported. To do this, we analyzed the 100 reports written by 20 future Belgian primary school teachers throughout their pre-service education: five reports each, one after each internship. We used a mixed-method approach to analyze the development of their reflective writing skills over these five occasions. Our results show that, despite the repetition, writing self-evaluation reports did not significantly improve the reflective writing skills of the student teachers in our sample. Little change occurred as the training progressed, while the few improvements we observed quickly gave way to a decline. Thus, our results reinforce the need to provide specific support for the development of reflective writing skills.