The long-term test-retest reliability of event-related potentials (ERP) measures was examined in a group of 44 controls and 71 chronic alcoholics, retested after an average of 14 months. Correlational analyses revealed moderately significant test-retest correlations for visual and auditory target N1, N2, and P3 amplitudes, with significant correlations for N1, N2 and P3 latencies. Controls and alcoholics produced similar test-retest correlations for visual and auditory ERP measures. Men and women produced equally stable ERP measures over time. Overall N1 and P3 amplitudes were most reliable in both groups followed by N2 amplitude, N1 and N2 latency, and P3 latency. The stability of ERP measures found in this study over a 14-month period in both normals and chronic alcoholics supports the use of ERPs in the study of normal and disordered cognitive functioning.