The present study compared alterations of event-related brain potentials (ERPs) in subgroups of chronic alcoholics with different complications during alcohol withdrawal. Twenty alcoholics with only mild to moderate alcohol withdrawal symptoms, two groups of alcoholics with histories of either delirium tremens (n = 9) or alcohol hallucinosis (n = 13), and a control group of 38 nonalcoholics were examined. Patients were tested in unmedicated state and not earlier than 14 days after drinking cessation. An auditory Oddball paradigm and a visual Letter Matching paradigm were used as cognitive tasks. In the auditory task, all alcoholic groups exhibited delayed N200 and P300 latencies and a reduced P300 amplitude as compared to nonalcoholics. In the visual task, only P300 amplitude was significantly diminished. Patients having suffered from delirium tremens or alcohol hallucinosis showed greater Oddball P300 amplitudes than alcoholics with uncomplicated withdrawal syndrome. Furthermore, delirium and hallucinosis patients differed in their ERPs, with hallucinosis patients showing an earlier P300 peak in both the auditory Oddball and the Letter Matching task. It is concluded that changes in ERPs during abstinence might reflect specific neurophysiological dysfunctions in alcoholics prone to different alcohol-related psychoses.