In this study, the effect of a frontal brake light (FBL) on children's willingness to cross the road was investigated. While recent studies have investigated effects of an FBL their samples consisted exclusively of adults. The results and conclusions of these studies may not be applicable to children due to their partially less developed cognitive capabilities. Accordingly, the aim of this study was to investigate the effects of an FBL on children's willingness to cross a vehicle's path. In a mixed design simulation study, participants were assigned to an experimental condition (EC), in which vehicles were equipped with an FBL, or to a control condition (CC), in which vehicles were not equipped with an FBL. Children aged six to twelve watched videos from the perspective of a pedestrian standing at the curb. A vehicle with an initial speed of 30 km/h approached either by maintaining the speed or by decelerating. In the latter case, the braking onset was varied (55 m or 32 m from the pedestrian's position). Participants’ task was to indicate their willingness to cross the road in front of the vehicle at five different distances. Results show that FBL affected the willingness to cross the road, especially at an early braking onset (i.e., 55 m). If the vehicle decelerated (i.e., the FBL was activated in the EC), the willingness was significantly higher in the EC than in the CC. In case the vehicle maintained its speed (i.e., the FBL was not activated in the EC), the opposite effect appeared. However, children did not exclusively rely on information gained by the FBL, but still paid attention to distance to the vehicle and braking onset. In conclusion, the effects of an FBL on children are similar to the effects on adults identified in prior studies. Nevertheless, more research in complex scenarios is needed to draw general conclusions about the impact of FBL on road safety in differently aged children and adults.