A recent study in human fetuses with myelomeningocele produced evidence that nonclosure of the spine leads to progressive damage of the exposed spinal cord during pregnancy. Thus in utero coverage might spare function. We tested the use of the latissimus dorsi flap for fetal myelomeningocele repair. In seven sheep fetuses, a lumbar myelomeningocele type of lesion was created at 75 days' gestation and was covered with a "reversed" latissimus dorsi flap at 100 days. At term, the three survivors had healed cutaneous wounds and normal hindlimb function. The vascular pedicle of the latissimus dorsi flap was patent, the viable flap covered the entire lesion, and the underlying spinal cord was grossly intact. We conclude that the latissimus dorsi flap repair is suitable for fetal surgery and provides efficient coverage of the lesion. These results have clinical implications, since fetal myelomeningocele repair may be a compelling way to reduce the severe neurologic deficit in humans.