Bicycling injury results in about 580,000 emergency room visits and 900 deaths each year in the United States. Alcohol involvement in bicycling injury has not been well documented in the literature. Using data from the Fatal Accident Reporting System, blood alcohol concentrations (BACs) among fatally injured bicyclists ages 15 years or older were examined for the years 1987-1991. Of 1711 bicyclists who were killed at age 15 or older and tested for alcohol, 32% were positive and 23% legally intoxicated. Adjusted for age, time of crash and other variables, male victims were 3.3 times as likely as female victims to be BAC positive, and 3.9 times as likely to be legally intoxicated. Victims ages 25 to 34 and those who died from night-time crashes also had significantly increased likelihood of being BAC positive and being legally intoxicated. Even among victims ages 15-19 who were legally prohibited from drinking, 14% had positive BACs. Further studies are needed to confirm the causal relationship between alcohol use and bicycling injury. Alcohol regulations for people biking on public roads should be seriously considered.