The burden of helminthiasis is high in Vietnam. Infection in young children can result in poor nutritional status and long-term consequences such as impaired growth and cognitive outcomes. Limited information linking maternal and infantile helminthiasis and nutritional outcomes in childhood exists. This longitudinal cohort study of women and infants who had previously participated in a cluster randomized trial of antenatal micronutrient supplementation in rural Vietnam examined the prevalence of soil-transmitted helminth infections in women at 12 and 36 months post-partum, and in children at 12 and 36 months of age. At 12 months post-partum, twenty four percent of women (237/988) had an intestinal parasitic infection. Infection with Trichuris trichiura (T. trichiura) was highest (19.1%). Only 1.5% of children were found to be infected with any parasite at 12 months of age (15/993). At 36 months of age, 4.5 % (41/908) of children were found to have a parasite infection. These infections were principally due to T. trichiura (2.3 %) and A. lumbricoides (2.0 %). Prevalence of helminth infection in mothers at 36 months post-partum was 14.3 % for T. trichiura, 4.5 % for A. lumbricoides and 4.7 % for hookworm. Maternal occupation, wealth index and male sex were found to be strong predictors of infection. The prevalence of soil-transmitted helminth infections in Vietnam, particularly trichuriasis, remains high among women of reproductive age. Public health measures should target risk factors and aim to improve efficacy of treatment against T. trichiura.