BACKGROUND: The Ages and Stages Questionnaire (ASQ), completed by parents and caregivers, has been shown to be an accurate tool for screening children who need further developmental assessment. AIMS: To assess the feasibility of using the French Canadian translation of the ASQ in an epidemiological cohort of children from the French general population. STUDY DESIGN: Follow-up study by postal questionnaire at 12 and 36 months, using the ASQ. SUBJECTS: 339 French families recruited at the birth of their child in 2006 in two hospitals in the Paris suburbs. OUTCOME MEASURE: Response rates and French ASQ results at 12 and 36 months. The ASQ was scored as indicated in the manual. RESULTS: A high response rate of 79% was observed at the children's 1st and 3rd birthdays. Parents were enthusiastic about participating; half of them wrote comments on the questionnaires, most of them positive. Low scores at the 12-month assessment were associated with birth characteristics such as prematurity and transfer to the neonatology unit after birth, whereas at 36 months they tended to be associated with both birth and family socio-demographic characteristics. CONCLUSIONS: Use of the French ASQ in a research cohort appears feasible as response rates were high. Moreover, known links between child development measured by ASQ and birth and social characteristics were observed. However, further French studies are needed to understand differences observed in 12-month ASQ gross motor scores compared with US norms. For research purposes, further analysis of the ASQ in innovative, quantitative approaches, is needed.