Nine newborns with ovarian cysts of various histologic type are reported, and 28 similar cases from the literature are reviewed. All nine cases were found on the first day of life. No child had any other congenital anomaly. The mothers of 2 of these girls had polyhydramnios. The key diagnostic procedure is intravenous urography. The total body opacification effect, indicating avascularity, occurred during urography in 8 infants. Torsion, infarction, hemorrhage, necrosis, and rupture each occurred in 1 or more of these 9 cases. In 1 infant, cysts arose from both ovaries. Surgical removal was readily accomplished and none of the cysts was malignant. No further problems have arisen in those 5 children it has been possible to follow.