Background: The compliance of the intensive care unit (ICU) nurses regarding infection control assessment is essential for safe and quality health care. It has been seen that the knowledge of ICU nurses about nosocomial infections (NIs) is not sufficient, and they do not apply standard-contamination precautions. Objectives: This study aimed to examine the knowledge and behaviors of intensive care nurses about NIs and related factors. Methods: This descriptive-observational research was carried out in the surgical intensive care units of three hospitals in Turkey. A total of 103 eligible nurses were included in the study. An 80% classification system was used to evaluate the data. Results: The mean score of nurses' knowledge about NIs prevention was 41.52 ± 2.86. The participants' mean knowledge scores on preventing ventilator-associated pneumonia, catheter-related bloodstream infection, catheter-related urinary tract infection, and surgical site infection were 15.86 ± 1.54, 13.08 ± 1.54, 5.98 ± 0.83, and 6.59 ± 0.95, respectively. The mean behavior score for NIs prevention was found as 15.86 ± 1.54. The participants' mean scores on prevention of ventilator-associated pneumonia, catheter-related bloodstream infection, catheter-related urinary tract infection, and surgical site infection were 6.93 ± 0.89, 4.77 ± 0.82, 4.67 ± 0.71, and 1.10 ± 0.31, respectively. The mean scores of female nurses' knowledge on NIs prevention were higher than males (P < 0.05). A statistically significant difference was found between the nurses' weekly working hours and their knowledge and behavior scores regarding NIs prevention (P < 0.05). Conclusions: It was determined that the knowledge and behaviors of intensive care nurses regarding the prevention of NIs were insufficient. Also, gender and weekly working hours contribute to knowledge and behaviors related to NIs prevention.