Gestational diabetes mellitus (GDM) is an increasingly serious health problem among pregnant women. Phytosterol-enriched spreads are known to reduce total cholesterol (TC) and low-density lipoprotein (LDL), but little is known about their effects on GDM. We aimed to examine the effect of the daily consumption of phytosterol-enriched spreads on both the maternal and neonatal outcomes of GDM patients. GDM patients during the third trimester of pregnancy were enrolled and assigned randomly to consume a regular spread or phytosterol-enriched spread daily until the end of their pregnancy. Maternal diabetic symptoms such as serum lipid profile, glucose and insulin metabolisms, as well as neonatal complications, were analyzed at the beginning and full-term. The daily consumption of the phytosterol-enriched spread exhibited significant beneficial effects on maternal diabetic symptoms, in terms of improved lipid compositions and glucose metabolism. Moreover, the incidence of neonatal complications was also significantly reduced by the phytosterol-enriched spread, in terms of birth weight, macrosomia, hypoglycemia, respiratory distress and Apgar scores. The daily consumption of a phytosterol-enriched spread is able to improve both the maternal and neonatal outcomes in GDM patients.