Objective: To assess knowledge, attitude and practice of nurses regarding oral health care in intensive care units. Material and Methods: Developed in a Reference Hospital of Recife, Brazil carried out from July to September 2013. Overall, 282 professionals participated through a questionnaire to evaluate KAP on oral health care. Data were analyzed using Stata 12.0. For comparison, the Student t test and ANOVA with 0.05 significance level were used. Results: 45 (16 %) were professional nurses and 237 (84 %) belonged to the nursing team. 71.1 % of nurses and 72 % of nursing technicians failed to adequately respond as to know the daily frequency of oral hygiene performance, 75.6% of the surveyed nurses were aware of the use of chlorhexidine; however, only 37.7% of technicians considered this substance appropriate. Regarding attitude among nursing technicians, from the 11 questions, only two reached more than 90% of requirements. Regarding practice, when it came to items of medical record entries about the care provided, the percentage of inadequacy was 35.6 % among nurses and 26.2 % among nursing technicians, and the oral cavity conditions of patients, the frequency was 35.6 % and 26.2 % respectively. The average practice among nursing technicians was higher among those who had technical expertise in oral care (p = 0.031). Conclusion: For nursing technicians in practice section, oral health activity can be compromised by those without technical expertise.