Context: Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to butyl paraben and overweight in childhood, with a stronger trend in girls. Objective: We therefore studied the association between parabens in maternal urine in third trimester and fat percentage in children aged 7 years. Design, Setting, and Participants: We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010 to 2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by dual X-ray absorptiometry in their children at age 7 years. Main Outcome Measurements: Total, gynoid, and android fat percentages and z-score for body mass index. Interventions: None. Results: Paraben exposure was low. In multivariate linear regressions, detection of butylparaben in maternal urine was associated with an increase of 17% [95% confidence intervals (CI) 3.0%, 32%] in total body fat percentage and an increase of 23% (95% CI 5.1%, 43%) in android fat percentage in boys, compared to boys whose mother had no detectable butylparaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl parabens and body composition were found, and no significant associations were seen in girls. Conclusion: Our findings suggest that parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development.