Background: Patients with HIV/AIDS have to face discrimination in the society and in health-care system. Knowledge regarding HIV/AIDS determine nurses attitude toward HIV/AIDS patients. It is worthwhile to assess existing knowledge of HIV/AIDS among nursing staff to understand the prevailing situation. Objectives: 1.To assess the knowledge about HIV/AIDS preventive measures in staff nurse in Bombay Hospital, Indore.2.To find out the association between knowledge score on preventive measures with the selected socio-economic variables. Materials and methods: Non-experimental research design was used for the study. Convenience sampling was used as sampling technique and 30 staff nurses working in Bombay Hospital, Indore were selected. Data collections were done with help of demographic Performa and structured knowledge questionnaires. Questionnaire included close-ended multiple-choice questions. Staff nurses responses were recorded and analyzed in the form of descriptive statistics such as frequency and percentages. Result: Majority of the respondent’s i.e.66.7% belongs to the age group of 21-23. 63.3% of respondents were B.Sc nurses. And 36.7% were GNM.Majority of the respondent’s i.e.56.7% had less than 1year of clinical experience. Majority of the respondent’s i.e.76.7% were females 93.3%of respondent are working in the ward Around 43.3% of respondents had attended seminar regarding the preventive measures of HIV/AIDS100% of the respondents having the previous knowledge of preventive measures of HIV/AIDS. The overall mean knowledge score was found to be 17 and the standard deviation score was found to be 2.4.It was found that 77% of the staff nurses had good knowledge regarding the preventives measures of HIV/AIDS. The chi-square test value showed that only one demographic variable i.e. sex had significant association with the knowledge score. So the findings show that the staff nurses had good knowledge regarding the preventive measures of HIV/AIDS. Conclusion: Conclusion of the study shows that majority of staff nurses working in Bombay Hospital, Indore have good knowledge about preventive measures of HIV/AIDS.