Event-related potentials (ERPs) constitute a useful and cost-effective method to assess the neural underpinnings of multiple cognitive processes. ERPs have been used to track changes in cognitive processes in longitudinal and clinical studies. However, few studies have assessed their test-retest reliability (i.e., their consistency across time). Therefore, in the current study, we aimed to assess the test-retest reliability of ERPs (P100, N100, P200, N200, P3b, lateralized readiness potentials) across three tasks. In two assessments separated by approximately 4 months, ERPs were recorded in 26 healthy participants, during two oddball tasks (motor and counting) and a stimulus-response compatibility paradigm. Pearson’s correlations and intraclass correlations were used to assess the test-retest reliability of ERPs. Correlations between ERPs elicited by the three tasks were assessed with Pearson’s correlations. Our analyses revealed moderate to very strong test-retest reliability for most ERP components across the three tasks. Test-retest reliability did not differ between the motor and counting oddball tasks. Most ERPs were also correlated across paradigms. Therefore, these results confirm that ERPs have the potential to be reliable markers to serve as robust assessment tools in longitudinal or clinical studies. (PsycInfo Database Record (c) 2022 APA, all rights reserved)