Background: Patients attending hospital emergency departments (ED) commonly cite the urgency and severity of their condition as the main reason for choosing the ED. However, the patients’ perception of urgency and severity may be different to the nurses’ perception of their urgency and severity, which is underpinned by their professional experience, knowledge, training and skills. This discordance may be a cause of patient dissatisfaction. The purpose of this study is to understand the extent of agreement/disagreement between the patient’s perceived priority and actual triage category and associated factors. Methods: A cross-sectional survey of 417 patients attending eight public hospital EDs in Queensland, Australia between March and May 2011 was conducted. The survey included patient’s perceived priority and other health-related, socio-demographic and perceptual factors. Patients’ triage category data were retrieved from their ED records and linked back to their survey data. Descriptive and multinomial logistic regression analyses were used. Results: Over 48 % of the respondents expected to be given higher priority than the actual triage category they were assigned; 31 % had their perceived priority matched with the triage category; and 20 % of the respondents expected a lower priority than the triage category they received (Kappa 0.07, p < 0.01). Patients who expected a higher priority tended to be more frequent users (≥3 times in the past six months), and to score higher on perceived seriousness, perceived urgency, and pain score compared to the patients whose perceived priority matched the triage category or anticipated a lower priority. In the multivariate analysis, only perceived urgency remained significantly associated with expected higher priority (OR = 1.27, 95 % CI: 1.14–1.43). Discussion: Our findings clearly confirmed the discrepancy between patient perception of urgency and staff assessment of urgency. This can have important implications particularly for the patients who underrate the urgency of their condition. Improved and open communication and the incorporation of the ‘patient voice’ into the triage process require understanding the patient’s perspectives and their involvement in the decision making process. Conclusions: Noted differences between patient and practitioner perception of clinical urgency were identifed in this study.