<p><strong>Objectives: </strong>The purpose of this study is to assess the knowledge regarding prevention of Sexually Transmitted Diseases (STD&rsquo;s) among Adolescent students in selected high schools, Aizawl, Mizoram.</p>

<p><strong>Methods: </strong>Evaluative research approach was used in which one group pre-test post-test design was used as a research design. As for the study 100 Adolescent high school students were selected using simple random sampling technique in a selected high school, Aizawl, Mizoram.</p>

<p><strong>Results: </strong>The study assessed STD knowledge across different demographics using Chi-square tests, categorizing knowledge into Inadequate (0&ndash;7), Average (8&ndash;11), and Adequate (&gt;11). A significant association was found between age and knowledge levels (p = 0.0356), with older students (17&ndash;18 years) showing the highest adequate knowledge, suggesting age and maturity contribute to awareness. However, no significant difference was observed between Class IX and Class X (p = 0.8482), indicating grade level alone does not influence knowledge. However, family structure showed significant effect (p = 0.0023) on the knowledge. Prior knowledge did not significantly impact post-intervention results (p = 0.2165), highlighting the effectiveness of structured education over informal sources. Additionally, the source of STD information (e.g., teachers,family,peer group, mass media) showed significant impact on knowledge levels (p = 0.0093), implying source from the teacher was dominant. Overall, age, types of family and sources of information was the factor significantly linked to knowledge.</p>

<p><strong>Conclusion: </strong>The study concluded after administering Planned Teaching Program (PTP), there is improvement in knowledge among the Adolescent high school students regarding prevention of Sexually Transmitted Diseases (STD&rsquo;s). Hence, it is statistically interpreted that Planned Teaching Program (PTP) was effective for the improvement of knowledge regarding prevention of Sexually Transmitted Diseases (STD&rsquo;s) among Adolescent high school students.</p>