Movements of the lower limbs during gait have been analysed extensively whereas data on upper body movements are scarce. The aim of this study was to evaluate upper body movements during gait in nine healthy children and 10 children with diplegic cerebral palsy. Children were investigated using a full-body marker set to calculate the upper body kinematics of trunk and arms. When the healthy children were compared with the children with cerebral palsy, the latter compensated more for their gait deviations and were less stable. This was expressed by their greater variability in arm movements and increased movements at the thorax. The thorax showed an increased forward tilt with greater range of motion over the gait cycle. The shoulders were more abducted with increased elbow flexion. Gait analysis with the full-body marker set has offered prospects for a better understanding of compensatory mechanisms for the pathological gait pattern in children with diplegic cerebral palsy.