HIV is not a disease in itself, it is a condition, which if not managed properly with a healthy lifestyle and habits, results into AIDS- a condition, where an individual’s immune system has been lost and the person becomes vulnerable to many illnesses. The setting for the study was SV degree college Thatithopu, Tirupati. A Non-probability convenient sampling technique was adopted to select 100 adolescents. A structured questionnaire and checklist was used to assess the knowledge and attitude on HIV/AIDS among adolescents.The collected data was analyzed using descriptive and inferential statistics. The results shown that 27% of adolescents had inadequate knowledge, 54% had moderate knowledge and 19% had adequate knowledge, and regarding attitude on HIV/AIDS 25% of adolescents had unfavorable attitude, 48% had moderately favorable attitude and 27% had favorable attitude and there is a significant association between level of knowledge regarding HIV/AIDS with mother’s educational status, mother’s occupation, father’s educational status, father’s occupation, place of residence, source of information  at P <0.01 level.