A flank protection for the protection of passengers from impacts of lateral areas of motor vehicles comprises a vehicle body side wall having a window, such as a door, wherein reinforcement for preventing excessive penetration of the vehicle by other vehicles is located solely in lower areas of the side wall, particularly in an outer body part, while an upper side wall portion is formed of inner and outer body parts, preferably above a belt line of the vehicle, are composed of resilient portions that are yieldable to the absorption of outwardly directed reaction forces applied by an occupant against said body parts above said belt line.