HIV-AIDS becomes a topic of global concerned today and India being the second largest populated country is on a high risk of prevalence. The most affected people by this deadly disease are youth (15-49 yrs) around the globe and so in India. As so far no cure was discovered for this epidemic, knowledge and awareness is the only left for prevention of this disease. Government of India and ministry of health have taken this issue very seriously and creating awareness through various sources. One such source is educating the youth by delivering the knowledge about epidemic at the school level as adolescence possess much vibrant characteristics than mature people and are on higher risk of prevalence. This survey based study was conducted among senior secondary school students to assess their knowledge and attitude towards HIV-AIDS as well as impact of knowledge on attitude and sex behaviour. This study was conducted among 400 students of Bilaspur selected through stratified random sampling based on type of school and gender of students. The findings of the study shows that knowledge and perception about the epidemic creates a positive impact on attitude towards HIV-AIDS by 83% whereas it creates an impact on sex behaviour at about 69%.