Background: Adolescents are fulcrum of population; it’s the window  period for adopt the risky behaviors and many health issues which may affect the health in the future. The aim and objective of the study was to evaluate the knowledge on health issues among adolescents residing in the Vellore district. Materials and methods: The descriptive, cross sectional study design was adopted. Through the non randomized convenient sampling technique, one hundred fifteen adolescents who are all in the age of 17 to 19 years were enrolled. The data were collected through 45 items multiple choice questionnaires by interview method. The collected data were analyzed by descriptive and inferential statistics. Results: Out of 115 adolescents, 81% had inadequate knowledge, 13% had moderate and remaining 6% only had adequate knowledge. The knowledge on health issues and utilization services was low among males as compared to female adolescents. The chi square value depicts that age, education and occupation had significant association with the knowledge score at p < 0.05. Conclusion: Hence, the poor knowledge makes adolescents face many difficulties to manage and prevent these issues. Thus, there is an urgent need of multi dimensional approach and educational instructional programs must be a vital part to promote their knowledge and achieve wholesome adolescent health. Keywords: Knowledge; Health Issues; Risk Behaviors; Utilization Services  and Adolescents.Adolescents are fulcrum of population; it’s the window  period for adopt the risky behaviors and many health issues which may affect the health in the future. The aim and objective of the study was to evaluate the knowledge on health issues among adolescents residing in the Vellore district. Materials and methods: The descriptive, cross sectional study design was adopted. Through the non randomized convenient sampling technique, one hundred fifteen adolescents who are all in the age of 17 to 19 years were enrolled. The data were collected through 45 items multiple choice questionnaires by interview method. The collected data were analyzed by descriptive and inferential statistics. Results: Out of 115 adolescents, 81% had inadequate knowledge, 13% had moderate and remaining 6% only had adequate knowledge. The knowledge on health issues and utilization services was low among males as compared to female adolescents. The chi square value depicts that age, education and occupation had significant association with the knowledge score at p < 0.05. Conclusion: Hence, the poor knowledge makes adolescents face many difficulties to manage and prevent these issues. Thus, there is an urgent need of multi dimensional approach and educational  instructional programs must be a vital part to promote their knowledge and achieve wholesome adolescent health.   

Keywords: Knowledge; Health Issues; Risk Behaviors; Utilization Services and Adolescents.