As a test of the applicability of modern bioengineering tools to pediatric surgery, we developed by computer-aided design (CAD) methods and evaluated a virtual reality (VR) model of laparoscopic pyloromyotomy (LP) and created a set of retractable hook instruments, called Pylorohooks. Our VR model of LP incorporated the infant's body wall, stomach, and hypertrophied pylorus as well as laparoscopic cannulas and two Pylorohooks. CAD software was used to design the 3-mm-diameter, retractable, double-pronged, minimally-traumatic hook instrument. A rapid prototype processor was employed to create a plastic model of the instrument. Surgical-grade stainless-steel prototypes were then manufactured and used in actual LPs. A working VR model was achieved. Following an initial correction in the angulation of the hooks, the instruments were successfully employed in nine consecutive LPs in infants weighing from 3.4 to 5.7 kg. VR and CAD thus proved instrumental in the development of a new LP approach. Because of increasing pressure to limit human and animal experimentation, computer-based bioengineering methods offer promising alternatives that are clearly applicable to pediatric surgery.