The selective non-operative management of penetrating abdominal injury is gaining increasing acceptance. Recognition of the morbidity, mortality, and cost associated with non-therapeutic exploration has provided the impetus for selective management. This review describes the principles of, and evidence for, this strategy. Selective management is widely accepted for the treatment of stab wounds, but the selective management of ballistic injuries, particularly in the military setting, remains contentious. As a result, there are marked variations in the application of this practice. Computed tomography is a prerequisite for the selective management of ballistic injuries, and possibly also stab wounds. Failure of non-operative management, following stab wounds or gunshot wounds, is invariably apparent within 24 hours.