Studies have shown that nurses have a crucial role in the recognition of delirium; however, they have insufficient knowledge regarding the issue.

The aim of the study is to determine the knowledge level of cardiovascular surgery nurses regarding delirium.

A survey design was used. The population of the study consisted of 124 nurses employed at the cardiovascular surgery wards and intensive care units of universities as well as state and private hospitals located in two different cities in Turkey between May and June 2014. The sample consisted of 97 nurses employed at the aforementioned institutions and time. Data were collected using the questionnaire form depicting the demographic characteristics of the nurses and the knowledge form including the level of nurses' knowledge regarding delirium. For the evaluation of data, number, percentage, Kruskal‐Wallis, Mann‐Whitney U‐ and independent‐samples t‐test were used.

Nurses were between 18 and 47 years of age with a mean 29·8 (SD = 6·80, the youngest = 18 and the oldest = 47) years. They spent a minimum of 1, a maximum of 25 and a median value of 3 (interquartile range, IQR: 5) years working in cardiovascular surgery. As for the scores received from the knowledge form regarding delirium, the lowest was zero, the highest was 60, and the average score was 41·18 ± 12·50 (a moderate level of knowledge). It was found that the nurses working in intensive care units, those who were chief nurses and those who received in‐service training scored higher than the others.

Cardiovascular surgery nurses had a moderate level of knowledge regarding delirium. This may result in the neglect of delirium or a misdiagnosis.

It is recommended that training is provided that includes recognition, assessment and application of appropriate interventions to minimise the incidence of delirium.