Among 173 fatally injured bicyclists, the head or neck was the region most seriously injured in 86%. The frequency of injury to the head and neck region and the frequency of nonsurvivable (AIS 6) injury were highest among the cases aged 16 years or less.Vertebral fractures occurred most often in the highest cervical vertebra (C1) and progressively less often in lower vertebrae. The relationship between vertebral position and fracture likelihood is approximately log linear.Bicyclists with a relatively long time from injury to death tended to be older persons with survivable injuries. They often died from complications (pneumonia, pulmonary embolus) rather than directly from their injuries.