Adolescence is a transitional phase from childhood to adulthood, when a young person enters a new word that challenges him to the developmental changes taking place within him/her. This study concluded that adolescent have less knowledge about their developmental changes. The intervention method was found to be effective in increasing the knowledge of young people. The result of the study shows that the information was added after the young people received information about the developmental changes taking place in the planned teaching programme. The general system theory was used as conceptual framework The pretest score was 8.20 and the posttest score after planned instruction was 23.5, indicating a significant difference after teaching. In addition, the study suggests that this research should be conducted on a large scale. With the help of this research, the knowledge and attitude towards developmental changes of young people can be assessed. Finally, the proposed educational program is effective in increasing the knowledge of youngsters.