Aim: To determine parental, especially paternal factors associated with the weight of the placenta and offspring. Methods: This population-based birth-cohort study includes 2947 singleton children born from April 2006 to 2007 and living in Drenthe, The Netherlands. Placental weight and birth weight were measured and questionnaires were filled out for this cohort. Associations between parental factors, and the weight of the placenta and the offspring were evaluated using univariate and multivariate linear regression models. Results: Univariate regression revealed that the paternal birth weight and body mass index (BMI) of the father were predictors for placental and birth weight of the offspring. However, they were not independent predictors. Independent predictors for placental weight were the maternal factors of pre-pregnancy BMI, birth weight, and diabetes. The maternal factors of weight gain during pregnancy, birth weight, smoking during pregnancy, and diabetes were independent predictors for birth weight of the offspring. Conclusion: Paternal as well as maternal factors influence the weight of the placenta and the offspring.