Background of the study: Adolescents are susceptible to diseases due to their limited awareness and lack of abilities in mitigating dangerous behaviors. The primary contributors to chronic diseases have been recognized as lifestyle risk factors, including smoking, alcoholism, dietary patterns, sedentary behavior, and physical inactivity.

Objective: The objective of this study was to assess the efficacy of a structured education program in enhancing information pertaining to health promotion behavior for the prevention of lifestyle illnesses among teenagers at Govt. Senior Secondary School, Pehrawar, Rohtak.

Methodology: The study was carried out on 100 adolescents utilizing a nonprobability convenient sampling technique and a quantitative approach with a pre-experimental one group pre-test and post-test design. A self-structured questionnaire schedule was used to measure adolescents' understanding of health promotion behavior and lifestyle illness prevention.

Results: The mean and standard deviation were used to describe the data, and the t-test was used to draw conclusions from the data. The average score on the pre-test was 10.9, and the standard deviation was 2.447. The average score on the post-test was 26.23, and the standard deviation was 2.309. The average difference between the scores on the pre-test and the post-test was 15.330, which is the same as the table number at the 0.05 level of significance.