Background Unintentional injuries need to be better studied to be avoided, as they are responsible for 25,000 deaths per year in France, including one a day in children under 15 years old. One of the objectives of “school surveys” is to describe these injuries, the conditions of their occurrence, their severity, their consequences in terms of limitations and healthcare, and the factors associated with the injury.

Methods The same questionnaire on the occurrence of injuries was used in three nationally representative samples in France: 17,000 schoolchildren aged 5–6 years in 2012–2013, 7,000 schoolchildren aged 10–11 in 2004–2005, and 7,000 students aged 14–15 in 2008–2009. The data were weighted; descriptive and multivariate analyses were performed.

Results In the three months preceding the survey, 4% of 5–6 year-olds, and 9% of 10–11 and 14–15 year-olds reported an injury. The proportion of traffic accidents was 10% at 14–15 years, and only 4% at 10–11 years and 2% at 5–6 years. The proportion of fractures was similar among the three samples, representing between 20% and 24%. Sprains increased with age: 8%, 33% and 54%. The head was the most affected part at 5–6 years (57%) and lower limbs at 10–11 years and 14–15 years (41 and 48%). Injuries were more frequent among boys in the three surveys, in middle class children, in children spending less time watching a screen, in children with a history of asthma or practicing a sport activity in the 14–15 years age group, and in overweight children in the 5–6 years age group. They were less frequent in 5–6 years and 10–11 years old children attending school in priority education zones.

Conclusions As all the children attend school in France, these results relate to all unintentional injuries of children of one age group. Further specific surveys on the most severe injuries are needed to define preventive actions.