In utero open surgery can salvage many fetuses with life-threatening anomalies. This approach carries risks, especially from preterm labor induced by the hysterotomy incision. In an effort to decrease uterine injury during hysterotomy, we developed techniques for endoscopic manipulation of the fetus. We developed these methods in fetal lambs. The uterus was exposed and insufflated with CO2. As a model for in utero surgery, a simulated cleft lip was created and immediately repaired using intracorporeal suturing and knot-tying procedures. The techniques for endoscopic suture placement and knot-tying were based on microsurgical principles. We also designed and created several specialized instruments to facilitate precise work in this highly magnified surgical field. The novel techniques of endoscopic fetal surgery described here offer an alternate approach to fetal intervention. Our future goals include the application of these techniques to a nonhuman primate model and the development of percutaneous access methods.