A definite health determines the overall wellbeing of a person. The perfect proportion of food and nutrition starting from our early stages of life plays a major role in the late adulthood. The study was aimed to identify the effectiveness of structured teaching programme on knowledge regarding healthy dietary habits among adolescents in selected schools, Alappuzha District, Kerala. Objectives: - 1. To assess the pretest and posttest knowledge regarding healthy dietary habits among adolescents in selected schools, Alappuzha District. 2. To evaluate the effectiveness of structured teaching programme on knowledge regarding healthy dietary habits among adolescents. 3. To determine the association between mean pretest score on knowledge regarding healthy dietary habits with selected demographic variables. Methodology: An evaluation approach with one group pretest-post-test design was used for the study. The convenient sampling technique was used to draw sixty Higher Secondary School children as samples. Data was collected by administering structured questionnaire on healthy dietary habits. Lesson plan along with appropriate AV aids had been used for teaching. On the 7th day, post test was conducted using the same questionnaire. The collected data was analyzed by statistical method. Result:- The analysis of pre-test knowledge revealed that among 60 samples half of them have average knowledge (50%), 41.66% have poor knowledge and remaining 8.33% have excellent knowledge. The post test revealed that there is increase in percentage of excellent knowledge (75%) remaining 25% have average knowledge and none of them have poor knowledge. Paired‘t’ value of knowledge was 13.58 which is greater than the table value and found statistically significant. Conclusion: - The study proved that the structured teaching programme was effective in improving the knowledge of healthy dietary habits among adolescents as evidenced by the significant change between pretest and post test values.