Objective: The objectives of this study were to find out the level of prejudice amongst doctors and nurses against people living with HIV (PLHIV) at a teaching and research hospital, and to determine the underlying factors of this prejudice. Methods: A 39-question survey was applied to 126 doctors and nurses in order to determine the demographic characteristics of participants and to measure the level of disease knowledge and level of prejudice against PLHIV. Correlation was found between participants' demographic characteristics and level of knowledge and prejudice. Participants' knowledge and prejudice levels were scored by assigning 1 point to correct answers while assigning zero to wrong answers in the section analyzing the relationship between the level of knowledge and prejudice. The relationship between these variables was shown on a scatter diagram and estimated by linear regression analysis. Results: Though lack of knowledge and prejudice against PLHIV was found to be high among all participants, high school graduates and nurses appeared to be less knowledgeable about and more prejudiced against PLHIV than university graduates and doctors. Having worked at infectious diseases and clinical microbiology department or having followed PLHIV before did not have any positive impact on the level of knowledge or prejudice. High level of knowledge was found to be associated with low level of prejudice. In addition, it was observed that factors other than the level of knowledge were also the cause of prejudice. Conclusions: Lack of knowledge is just one of the causes of prejudice against PLHIV among health personnel. Health personnel have to be informed about PLHIV to lessen existing prejudice, and other factors that may result in prejudice need to be further researched. Klimik Dergisi 2014; 27(3): 103-8.