We performed a multicenter case-control study to estimate whether chronic alcoholism and alcohol consumption are risk factors for developing a first generalized tonic-clonic seizure (GTCS). We studied 237 first-seizure patients (158 men, 79 women) matched to 474 hospital controls for center, sex, age (+/-5 years), and weekday of the seizure. The risk of first GTCS in alcoholics was greater than in non-alcoholics for men (odds ratio, 6.8; 95% confidence limits, 3.6-13.0) and women (6.8, 1.6-32.6). The odds ratio (both sexes) was 1.2 (0.8-1.8) for an average daily intake of absolute alcohol of 1 to 25 g/day and rose with the amount of alcohol consumed daily: 1.3 (0.8-2.1) for 26 to 50 g/day, 3.0 (1.7-5.4) for 51 to 100 g/day, 7.9 (2.9-21.9) for 101 to 200 g/day, and 16.6 (1.9-373.4) for >200 g/day. Our study provides evidence of a powerful association between alcohol use, alcoholism, and the first GTCS.