Introduction: Junk food comprises of anything that is quick, tasty, convenient and fashionable. It seems to have engulfed every age, every race and the newest entrance in student. Students are experiencing so much growth they may always feel hungry. He or she may come to the dinner table ready to eat anything. Eating right and being physically active are not just a diet or a program. These are the key to a healthy life style. With the healthful habits we may reduce our risk of many chronic diseases such as heart disease. Many of the junk foods are high on carbohydrates, low on fiber, heavy on fat with little vitamin content. Junk Food includes those food items that do not add any value to a person’s diet. Here, value denotes essential nutrients, vitamins & minerals. Street food and fast food are also taken in the same context as junk Objective: To assess the pre-test level of knowledge regarding harmful effects of junk food consumption among undergraduate students, To evaluate the effectiveness of structured teaching programme on knowledge regarding harmful effects of junk food consumption among undergraduate students. To find out association between the post-test level of knowledge Score regarding harmful effects of junk food consumption with selected demographic variables. Methodology: The research design which is used to achieve objectives of this study is non- experimental, Descriptive Design. The population was mothers of under-five children. The sample consists of 60 undergraduate students at selected college at vadnagar. The data was collected from undergraduate students using a structured questionnaire for knowledge. The data obtained was analyzed by using descriptive and inferential statistics. Result: The data presented in the mean post-test knowledge score (22.26±3.95) was higher than the mean pre-test knowledge score (8.41±5.16). The calculated’ value (21.24) was greater than the table value (1.67) at 0.05 level of significance that shows the structured teaching programme was effective in increasing the knowledge of undergraduate students. Conclusion: This study finding concluded that structured teaching programme on junk food consumption was effective in improving the knowledge among undergraduate students.