We examined whether deficits in planning and control during a manual collision avoidance task in children with hemiparesis are associated with damage to the left or right hemisphere (LHD and RHD). Children pushed a doll across a scale-size road between two approaching toy cars. Movement onset and velocity served as indicators of planning and control. In Experiment 1, children with hemiparesis collided more frequently, and controlled velocity less appropriately compared to typically-developing children. Children with LHD initiated their movement later than children with RHD. Experiment 2 compared the preferred and non-preferred hand of children with LHD and RHD. Children with RHD crossed less with their non-preferred hand, while children with LHD initiated later than children with RHD. Moreover, the groups showed differences in velocity control. It is argued that planning deficits may be related to LHD. The hypothesized association between control deficits and RHD, however, was not confirmed.