Objective: We investigated the effects of probiotic yogurt administration to mothers during late pregnancy on intestinal microbiota and the incidence rate of atopic eczema in infants at one year of age. Methods: Eighteen pregnant women were given 100 g of yogurt containing Lactobacillus rhamnosus GG (LGG), from day 1 of the 33rd week of gestation until parturition (LGG group), and the results obtained from their newborns were compared to those from infants born to 14 mothers who had not received this probiotic treatment (Control group). Lactobacillus GG bacteria (LGG bacteria) in infants’ feces at 4 and 6 months of age were compared using quantitative polymerase chain reaction. The relationship between the detection rate of LGG bacteria and the presence or absence of eczema at the age of one year was evaluated. Results: The LGG bacteria detection rate at 4 months was significantly higher in the LGG than in control group (p<0.05), with a lower incidence rate of eczema in the LGG than in the control group (p<0.05). Among infants with eczema at 4 and 6 months, the rate of eczema clearing at 1 year was higher for the LGG than the control group (p<0.05). Administering LGG to pregnant women was effective in lower the incidence of eczema at 1 year, regardless of the LGG bacteria in infants (p<0.03). Conclusion: Giving LGG yogurt probiotics to pregnant women during late pregnancy is useful in preventing eczema in infants at 1 year of age.