The aim of this study was to identify the status of education and knowledge concerning oral diseases for oral care as they relate to intensive care unit (ICU) nurses, as well as to investigate the perception of oral care education and practice, as led by dental experts. This study conducted a self-report survey consisting of 33 questions on education and knowledge about oral diseases, as well as perception of dental expert-led education and practice, targeting 240 nurses in the ICU. Finally, 227 questionnaires were analyzed, and 75.3% of the participants were staff nurses, and 41.4% were in the medical ICU. In the area of education and knowledge of major oral diseases, more than 50% of the respondents treating gingivitis, periodontitis, and dental caries did not complete dental education, and it was found that more than half of the respondents were unable to distinguish diseases of the mouth. It was recognized that more than half of nurses required dental expert-led education and practice. In this study, the education and knowledge of oral diseases of ICU nurses were found to be insufficient, and the need for the cooperation of dental experts was high. Therefore, collaboration to improve oral care practical guidelines for realistically applicable ICU patients will be needed.