This quasi-experimental study aims to determine EFL learners' speaking self-efficacy levels and to examine the changes in oral performances after receiving feedback in three module courses. The relationship between speaking self-efficacy and oral performances after receiving feedback was also studied. Quantitative method was applied in this study. The study was conducted among thirty-three EFL prep-school participants in a state university in Turkey. The research began with the implementation of a speaking self-efficacy scale (pretest) and a speaking test. This process was followed by three oral treatments following teacher and peer feedback and the same speaking test. Repeated treatments and the same speaking test were conducted in the other two modules, as well as a final speaking self-efficacy scale (post-test). The results of the speaking self-efficacy scale revealed that students generally possess high speaking self-efficacy level. The findings also showed that students demonstrated significant changes in their oral performances following feedback treatment in both groups. In the final speaking test, participants who received teacher and peer feedback improved by 212.36% and 161.20% respectively compared to the first speaking test. However, no significant correlation between the two variables was observed. This may suggest that the sample size was insufficient to observe such a relationship.