Fetal chest masses are uncommonly noted on obstetrical ultrasound examinations. Some masses will undergo in utero regression with no neonatal morbidity whereas others are almost universally fatal. An accurate prenatal diagnosis is essential in enhancing parental decision-making. This paper reviews the published literature of two specific kinds of prenatally diagnosed fetal chest masses (congenital cystic adenomatoid malformations and pulmonary sequestrations) with emphasis on ultrasound characteristics and pregnancy outcome.