Active school transportation (AST) can contribute substantially to children's daily physical activity, yet AST has been declining. Social norms may influence parents' decision-making. This study advances the understanding of normative beliefs by including motivation to comply and identification with the referent. The aim was first to describe parents' normative beliefs about letting their child walk or cycle to school and second, to explore how these beliefs were associated with parents' intentions. The descriptive and injunctive norm were moderate to relatively high among parents, whereas motivation to comply, identification with the referent, and the aggregated measures were low. Among these normative beliefs, only the descriptive norm was significantly associated with parents' intentions in the final multivariable model. Interventions should emphasize social approval by making others' behaviors visible, rather than focusing on parents conforming to social pressure.