Education in end-of-life care (EoLC) is essential for improving the knowledge, attitudes and behaviours of intensive care nurses. This study aimed to evaluate the effect of online awareness education, based on the End-of-Life Nursing Education Consortium, on the knowledge levels, attitudes and behaviours of intensive care nurses. This single-centre randomized controlled study. This study was performed in a tertiary intensive care unit in a university-affiliated hospital. Seventy-six intensive care nurses were selected and equally randomized. In the education, the group was given an EoLC awareness education programme on an online platform as 40-60-min sessions once a week for 4 weeks. The descriptive Information Form, EoLC Knowledge Test and the Nurses' Attitudes and Behaviours towards the EoLC Scale were used. In the study, intensive care nurses' knowledge, attitude and behaviour levels towards EoLC were evaluated before and after 4 weeks (±3 days) following the education. When the mean post-education scores of the nurses in the education group were compared with the control group, it was found that their mean scores on the EoLC Knowledge Test (p = .001, Cohen's d = 1.354, 95% CI = 3.240-6.549), the attitude sub-dimension (p = .001, Cohen's d = 1.520, 95% CI = 4.510-7.858), the behaviour sub-dimension (p = .001, Cohen's d = 1.425, 95% CI = 3.206-6.214) and the total attitude and behaviour (p = .001, Cohen's d = 1.927, 95% CI = 8.408-13.643) were statistically significantly higher than those of the control group. This study showed that EoLC awareness education positively affected nurses' knowledge, attitudes and behaviours. Accordingly, planning EoLC awareness education online at regular intervals may be recommended for intensive care nurses. Intensive care nurses may be given online EoLC awareness education to positively affect their knowledge, attitudes and behaviours about EoLC. Online EoLC education can be effective in terms of reaching a large number of nurses, time and cost.