The vast majority of adolescents aged 12 to 17 consider themselves to be in good health. However, studies on factors related to their behaviors and lifestyles, as well as their use of the healthcare system, show that this view must be qualified. Although adolescents appear in many respects to be healthier than adults, they are also subject to certain specific risks. Furthermore, this age group is not homogeneous, with distinct health issues between boys and girls. For instance, adolescents have contrasting dietary habits: they are the group whose daily intake of fruits and vegetables is furthest from the recommendations established by the National Nutrition and Health Plan (PNNS), yet they are also the group that consumes the most grains and starchy foods. They engage in more physical activity than adults and are also less affected by overweight and obesity. Regarding “risky” behaviors, patterns vary significantly by gender: cannabis use is on the rise and primarily affects boys, as do violent behaviors, while girls are more prone to depression and suicide attempts. Adolescents’ use of healthcare services also has specific characteristics. Their use of emergency services is significant, primarily for trauma and, starting at age 15, following traffic accidents. Hospitalizations are relatively rare and are mainly due to dental problems, trauma, or poisoning. Regarding psychiatric follow-up, an increasing number of adolescents are receiving care, particularly girls aged 15 and older for neurotic disorders. Finally, the mortality rate among boys aged 15 to 19 is much higher than that of girls, primarily due to suicides and traffic accidents. [author’s abstract]