Epidemiological studies on bicycle accidents show that a substantial fraction of the cyclists that call for medical aid, are suffering from skull and brain damage. The aim of the research performed at the K.U.Leuven is to reduce the risk of serious head injuries by the creation of a new type of bicycle helmet. To achieve this goal, a clinical review of pedal cyclist head lesions has been performed, a 3D accident simulation program has been developed, skull behaviour during impact testing has been studied and the current protective effect of a typical series of bicycle helmet has been evaluated. The absence of a temple cover allows a potentially dangerous contact between the temple of the head and the impact surface [1].