Teratoma is the most common tumor in newborns. In spite of reaching huge proportions and containing big blood vessels which deprive the growing fetus of blood, they show low mortality in the neonatal period. This is a presentation of a case where fetal ultrasonography is used for the study of a dichorionic tri-amniotic tripletmultiple pregnancy, in which a mixed tumoral mass, predominantly echogenic, with well defined borders, measuring 5, 8 mm, suggesting meningocele or sacrococcygeal teratoma, at the sacral level, was detected in one of the fetuses. After 15 days the tumor measured 16, 4 mm. In view of the absence of cerebral signs of Chiaris disease, the suspicion of a sacrococcygeal teratoma grows stronger. The pregnancy was interrupted by cesarean section at 35 weeks of gestation. The neonate with the congenital anomaly underwent corrective surgical treatment with satisfactory results, but necessity of new surgical interventions (AU)