Immediate complications can arise due to faulty implantation of material during fusion procedures, but none have been reported in connection with ablation of material in the spine. We report a case of intraperitoneal migration of a pedicle screw during attempted removal. It crossed the psoas muscle and perforated a small-intestine loop, triggering hemorrhagic shock and peritonitis by perforation. We analyze the causes and mechanisms underlying this exceptional case of migration, with a view to sharing preventive measures. Initial extra-pedicular screw positioning and the pressure exerted to remove it were responsible for this serious incident.