Sacrococcygeal teratoma (SCT) is a congenital germ cell tumor arising in the presacral area, and occurs in approximately 1 in 35,000 to 40,000 live birth. It is the most common neonatal tumor. Although these tumors are usually benign, malignant degeneration is common and the degeneration rate increases as a fetus ages. Therefore early prenatal diagnosis and treatment are very important. We experienced a case of SCT which was detected by ultrasonography at 28week gestation and report this case with a brief review of the literatures.