Teratomas of the umbilical cord are very rare lesions. We found only five cases in the literature from 1887 to 1993, the latest reported in 1985. We report a case of a 10 x 7 x 5-cm mass located just at the end of an omphalocele in the umbilical cord of a full-term baby. The mass exhibited something like a cranial and a caudal pole, and tissues of all three germinal layers could be found, but there were no skeletal structures. Therefore, this lesion was diagnosed as a teratoma of the umbilical cord. We review the literature and discuss the relationship between the teratoma of the umbilical cord and the holoacardius amorphus.