Background: Each and every HIV positive patient is a potential candidate for disease transmission to the attending health care workers. In future prospect, nursing students are one of the important components of health care delivery system. So they must have proper awareness and knowledge of epidemiology of HIV/AIDS. The accidental transmission of HIV infection to health care workers during occupational exposure is one real threat in world. Objective: The objective of the study is to know the existing knowledge about HIV/AIDS among nursing students in Tirupati. Materials and Methods: This is a Cross-sectional study done among 196 B.Sc nursing students during december 2012. A pretested, predesigned questionnaire containing questions regarding various epidemiological factors of HIV/AIDS was used. Data was collected from the nursing students after taking the consent. Data was entered into Excel Sheet and analyzed using epi info software 3.5.1 version. Results & Recommendations: Deficiencies with regard to HIV transmission, high risk groups, PEP availability was found among study subjects. In the present study, 24.2% had misconception that HIV spreads through insect bite, cough, sneezing, shaking hands etc. 28% & 33% don’t know that HIV can be transmitted by vaginal fluids & semen respectively. There is a need to assess knowledge regarding HIV/AIDS and any deficiencies are imparted as required.