Individuals assess their cognitive abilities in different situations, however, those self-estimates are rather inaccurate. In two experiments (each N=200), we investigated whether performance feedback improves the accuracy of self-estimates. Our participants performed cognitive tasks and estimated their abilities beforehand. One half of participants received feedback on their performance, whereas the other half did not. Then, all participants estimated their abilities and performed each task again. Surprisingly, performance feedback did not impact the accuracy of self-estimates for numerical, verbal, and spatial abilities. For working memory abilities, we observed the expected interaction: While the groups did not differ in their accuracy before the manipulation, the feedback group showed more accurate self-estimates after receiving feedback than the no feedback group. Thus, feedback might foster self-knowledge–but only for specific abilities. Overall, the correlations between performance ratings and performance got higher over time in both groups, suggesting positive effects of practice on self-estimates.