The authors designed this study to evaluate the prevalence and magnitude of heavy drinking among college students in celebrating their 21st birthdays and the impact of a birthday card suggesting moderation. The authors randomly assigned subjects to receive or not receive the card approximately 1 week prior to their birthday. Approximately 1 week after turning 21, the authors sent surveys to all subjects. Results based on 164 returned surveys indicated that 90% consumed alcohol, 75% went to a bar, 61% reached a blood alcohol content (BAC) above the legal driving limit, and 23% reached a BAC above .25. Results were similar for men and women. Although subjects generally liked the birthday card, it had no impact on their drinking or celebration plans. Findings suggest the need for additional attention focusing on specific alcohol-related events and further development of prevention approaches that are event specific. (Contains 1 note.)