We report the prenatal detection of increased nuchal translucency and decreased fetal movements, at 11 weeks of gestation, in a fetus at risk for Zellweger syndrome. The diagnosis of Zellweger syndrome was confirmed by metabolic studies on cultured chorionic villus sampling (CVS) cells and the pregnancy was terminated. The couple's subsequent pregnancy was monitored using the same method. In this pregnancy the nuchal translucency measured at 12 weeks' gestation was normal, the fetus was active, and biochemical studies using CVS and amniocentesis confirmed normal results. We believe this to be the first reported case of Zellweger syndrome followed prenatally in which an increased nuchal translucency and fetal hypokinesia were detected in the first trimester. During the pregnancy with the affected child the maternal serum screen (MSS) showed low estriol level. We believe this to be the second report of a low estriol level on MSS in a pregnancy affected with Zellweger syndrome.