As clinical entity, collodion baby represents a phenotype for a number of genotypes. Diffuse, platelike, dark scales that are characteristically attached centrally and freed at the edges gradually replace this collodion membrane. The condition is rare, accounting for 1 in 50,000 to 1 in 100,000 delivery. The condition is associated with major risks during the neonatal period. Complications include marked temperature instability, defective barrier function, increased insensible water loss predisposing to hypernatremic dehydration and pneumonia secondary to aspiration of squamous material in the amniotic fluid. We present a case of collodion baby. The main interest of this case was prenatal sonographic findings. Ultrasound examination revealed hyperechogenic amniotic fluid and intragastric mass. Postnatally, we confirmed collodion baby and keratinocyte plugs on stomach and amniotic fluid. The Korean Journal of Ultrasound in Obstetrics and Gynecology 10(3):145-149, 2008