We studied alcohol use before the onset of a first seizure in 308 patients with seizures and 294 controls. The risk of seizures increased with increasing current alcohol use. For unprovoked seizures (i.e., seizures occurring without an antecedent event, such as a recent stroke), the adjusted odds ratios rose from 3-fold at intakes of 51 to 100 g of ethanol per day (95 percent confidence limits, 1.3 and 6.3), to 8-fold at 101 to 200 g per day (95 percent confidence limits, 3.3 and 18.7), and to almost 20-fold at 201 to 300 g per day (95 percent confidence limits, 6.1 and 6.2). For provoked seizures, the odds ratios were lower and statistically significant only above 200 g per day (odds ratio, 10.1; 95 percent confidence limits, 2.3 and 43.8 at 201 to 300 g per day; odds ratio, 7.4; 95 percent confidence limits, 1.8 and 30.5 above 300 g per day). Among ex-drinkers (abstention greater than or equal to 1 year), no increased risk was detected. Alcohol withdrawal was not associated with the onset of seizures in this study; 16 percent of first seizures in drinkers fell outside the conventionally defined withdrawal period, and the remainder exhibited a seemingly random timing after the last drink. We conclude that the relation of seizures to alcohol use is dose dependent and appears to be causal, and that seizures can be interpreted as a disorder induced by the ingestion of alcohol, independently of alcohol withdrawal.