Objective: This study was carried out on the auxiliary staff working in a university hospital, to assess their knowledge and attitudes about nosocomial infections (NI). Methods: A questionnaire was used to collect the data, including questions related to the subject. The questionnaire consists of two parts. The first part includes some questions aiming to determine the socio-demographic characteristics and working status of the participants. In the second part, there is a list of questions intended to detect the knowledge and attitudes about NI. The knowledge related questions were scored and the assessment was made out of 100 points, whereas the attitude related questions were assessed in percentage (%) terms. Results: 32.1% of auxiliary staff stated that they wash their hands before each treatment, whereas 14.1% of them wash hands after each treatment. Moreover, 83.1% of staff use soapy water for washing their hands. The percentage of the auxiliary staff who could make the color separation of medical, household and recyclable waste bags thoroughly was found to be 6%. In order to protect themselves from NI while they are carrying out their duties, 38.1% of the auxiliary staff said that they wear gloves, 26.3% of them said that they use masks and 21.2% of them said that they wash their hands. The mean score of the auxiliary staff on knowledge related questions about NI was 40.9 ± 15.7 points. Conclusion: It was concluded that the auxiliary staff are not aware of their own role in preventing infection and they are also not aware of the importance of NI.Organizing in-service training programs for auxiliary staff to develop an understanding of the importance of NI and to make the auxiliary staff realize their rolein preventing these infections, ensuring continuity of these training programs and keeping them up-todate, and emphasizing the knowledge and subjects that indicate insufficient transference of knowledge to behavior can play a significant role in the preventionand control of NI.