Introduction: Adolescence is the transitional phase of growth and development between childhood and adulthood. The child's emotional, biological, and social development occurs during this time. Childhood obesity is a serious medical condition where excess body fat negatively affects children and adolescent’s health or well-being. It often causes health concerns such as overweight and obese adolescents are at an increased risk of developing comorbidities like type 2 diabetes, insulin resistance, high blood pressure, heart diseases and high cholesterol, social and mental problems etc.

Methods: Non-experimental descriptive research was adopted for this study. The study was conducted in selected school, Coimbatore district. 30 samples were selected by using non-probability convenience sampling technique. Semi Structured questionnaire was used to assess the level of knowledge regarding childhood obesity among adolescents.

Results: The study results showed that with regard to level of knowledge regarding childhood obesity among adolescents, 3(10.0%) had inadequate knowledge, 26(86.7%) had moderately adequate knowledge, 1 (3.3%) had adequate knowledge.

Conclusion: The study concluded that majority of adolescents had moderately adequate knowledge regarding childhood obesity. So there is a need to improve knowledge among adolescents.