Bicycle accident and injury data collected by two different samples of North Carolina hospital emergency rooms during the summers of 1985 and 1986 are examined and compared with state police-reported bicycle accident data for the same time periods. Of the 649 emergency room treated bicyclists, 62% were children aged 5-14 and 70% were male. Nineteen percent of the riders suffered moderate or worse injuries (AIS greater than or equal to 2), and 6% were hospitalized. In contrast, less than half of the police-reported accidents involved riders under 15 years of age, 85% of the riders were male, and two-thirds suffered moderate or worse injury. Whereas virtually all of the police-reported accidents involved a motor vehicle, less than a fifth of the emergency room cases did. Only 10% of the emergency room cases were duplicated on the state accident files. It is estimated that 800 children ages 0-19 are hospitalized annually in North Carolina for bicycle-related injuries, and an additional 13,300 children receive emergency room treatment.