Bicycle crashes are a major cause of injuries in childhood. The goal of this study was to determine the long-term disabilities caused by bicycle-related injuries, and to clarify the long-term treatment priorities of injured children. Hospital records of 372 children (ages 2-15 yr, median 9 yr; 232 boys and 140 girls) admitted with bicycle-related injuries from 1979 through 1986 provided clinical information, social service visits, in-hospital and outpatient rehabilitative interventions, and physical status at discharge. More complete evaluations were made by contacting parents by telephone (82 children), and by personal interview and physical examinations (27). Head injuries predominated (69.1%). Twelve (3.2%) died, all from major head injuries. Four suffered permanent severe impairment from cervical spinal injuries and head injuries and remain institutionalized (1.4%). One third had a persistent disability noted at the time of discharge in the medical record (33.6%), reported by telephone interview (31.7%), or confirmed by physical examination (37.0%). Still, only 11.0% received physical therapy consultations during hospitalization, and 22.8% received social service assistance. Only 39.0% were seen by a surgeon or pediatrician after discharge, and few (7.3%) received outpatient physical therapy. Cognitive or behavior changes were noted in 31.7%, many noting changes in school performance (worse in 20.7%), behavior (13.4%), and sleep, particularly nightmares (34.1%). Recurrent injuries occurred in 52 children (14.4%), of whom ten (2.8%) required further hospital admission. Bicycle-related injuries cause significant short- and long-term disabilities among children.(ABSTRACT TRUNCATED AT 250 WORDS)