The aim of this research is to determine the effect of e-portfolio application on reflective thinking and learning motivation of primary school teacher candidates. The study group of the research consists of primary school teacher candidates studying in the 3rd year of the Faculty of Education of a state university in Ankara. In the research, a quasi-experimental design with pretest-posttest control group was used. Quantitative data of the study were collected using the Learning motivation scale, Reflective thinking scale and Performance tasks and independent samples t-test, two-factor ANOVA for mixed designs and Mann Whitney U-Test were used in the analysis of quantitative data. The qualitative data of the study were collected by applying a semi-structured interview form to the primary school teacher candidates in the experimental group through the interview technique. In addition, content analysis method was used in the analysis of qualitative data. When the results obtained from the research were examined, it was seen that there was a significant difference in favour of the experimental group in terms of reflective thinking post-test mean scores. Moreover, when the significance of the difference between the post-test mean scores in terms of learning motivation was examined, it was seen that there was a significant difference in favour of the experimental group. It was determined that there was a significant difference between the experimental and control groups in favour of the experimental group in terms of the performance tasks administered to the primary school teacher candidates. As a result, it was concluded that e-portfolio applications have a positive effect on reflective thinking, learning motivation and performance tasks of primary school teacher candidates.