Cystic and solid tumors of the ovary are rare during the newborn period and infancy. We present the case of a term female infant born to a mother with 24 years of age and found to have a cystic abdominal mass through prenatal sonographic evaluation in the third trimester. The cyst was also demonstrated by postnatal abdominal ultrasonography. Because of the clinical and radiological findings of intestinal obstruction, laparatomy was performed at the age of three days and a cyst of 10' 8' 8 cm was found in the right ovary. Pathological examination of cyst revealed a teach-lutein cyst.