Myocardial Infarction is a leading cause of death in industrial nations. Even in a developing country like India, it is emerging as a major public Health problem. World Health Organization predicts that CAD will become the major cause of death in almost all countries by 2020 This study was aimed to assess the effectiveness of Structured Teaching Programme on Prevention of Myocardial Infarction among Young Adults residing at selected villages in Kirumampakkam Primary Health Centre, Puducherry. The study was conducted in two villages Manapet and Moorthikuppam, 60 young adults were selected by using non probability convenience sampling technique and pre- experimental one group pre-test post-test research design was adopted for this study. The study result shows that the paired “t”- test value of knowledge is ‘t’=25.05 at p<0.0001, Hence it is very highly significant, The paired test “t” value of attitude is t'=10.902 at p<0.001 it is highly significant and the paired test “t” value of practice is t'=6.051 at p<0.01 it is significant. The pre test and post test mean difference for knowledge, attitude and practice was 6.80, 19.3, 2.3 respectively. Thus there is a significant difference between pre-test and post-test score of knowledge, attitude and practice. Hence there is significant improvement in post- test level of knowledge, attitude, and practice, hence it is highly effective.