A prototype of an abdomen for injury detection in side-impacts is developed. This design can in principle be built into existing side-impact dummies. Necessary biomechanical data was obtained from free-fall studies with cadavers simulating impacts with intruding doors.The design consists of a structure with built in tolerance limits and injury detection is obtained by a single channel go/no-go signal; thus complicated continuous force and penetration measurements are avoided. The abdomen has a rigid penetration stop at the critical tolerance level. This stop is covered by a composite material giving stiffness characteristics identical to the human abdomen. Coded contact switches activated by springs when a critical load is exceeded are mounted between this material and the rigid stop.The abdomen is presented in detail together with the results of impact tests. The materials for the abdomen were selected with assistence of a computer aided design study described in this paper.The interfacing with some existing dummies and a possible extension to frontal abdomen injury detection is discussed.