Objective: Outdoor play makes a significant contribution to overall physical activity among young children. Our objective is to describe, using data from the National Nutrition and Health Survey (ENNS, 2006–2007), the outdoor play habits of children aged 3 to 10 years and to examine their relationships with sociodemographic characteristics, body mass, and sedentary behavior. Methods: The ENNS was conducted on a random sample of the population residing in metropolitan France. Data on children aged 3 to 10 were collected in face-to-face interviews by dietitians; 808 children were included in the study. The number of days on which the child engaged in outdoor play and the time spent watching television, using a computer, or playing video games were recorded separately for school days and days with little or no school. Logistic regression analyses were conducted. Results: On school days, 39% of children aged 3 to 10 never played outdoors. Only 50% of children played outdoors at least 2 school days per week. This proportion was significantly lower among overweight or obese children (33%) than among those of normal weight (52%), and among children spending 2 hours or more per day watching television (37%) compared to those watching less than 2 hours per day (56%). Outdoor play was also less common among children living in the Paris metropolitan area, among those from households where the primary caregiver was an "employee or laborer," or where household income per consumption unit was in the lowest 15% or highest 15%. Conclusion: Interventions should be implemented to facilitate and encourage outdoor play among children aged 3 to 10 in order to increase their overall level of physical activity, particularly for the most sedentary children or those with the highest body mass index.