Head injury associated with bicycle-related crashes is experienced disproportionately by children under age 20. Helmets are effective, but usage of helmets by children is minimal. This descriptive study, conducted in a small academic community with an ordinance requiring helmet use by children under 16, examined the views of parents and guardians about a bicycle helmet law and reports of helmet use in their families. Telephone interviews were conducted with a random sample of parents/guardians of third-, fourth-, and fifth-grade children (n = 142, 73% response rate). Sixty-five percent of those surveyed were aware of the ordinance. The vast majority (90%) agreed that bicycle helmet laws are "a good idea." Since the community helmet law was implemented, reported child helmet use increased, most notably among children who had never worn a helmet before the ordinance. Seventy percent of children who had never worn a helmet wore one most or all of the time since the ordinance. The ordinance also appears to have prompted parents to make helmet use rules for their children. Before the ordinance, families with rules reported helmet use by 79% of youths at least most of the time. This figure increased to 86% in families with rules after the ordinance was implemented. Even among the families without rules, helmet use increased from 7% before the ordinance to 60% after the law was enacted, indicating that both the ordinance and family rules are influential.