IntroductionEmergency department clinicians, and particularly nurses in triage, frequently perform routine blood tests on patients whose allocated triage category is not time critical (triage categories 3, 4 and 5 of the Australasian Triage Scale). Some observers have questioned the utility of routine blood testing in these acute healthcare settings given the cost and workload implications.MethodsA quantitative method using retrospective observational design was utilised guided by STROBE checklist. Electronic medical records of patient data collected at a quaternary Australian metropolitan hospital emergency department were reviewed.Results and discussionA total of 74,878 adult patients attended the emergency department between 1st January and 31st December 2021 and a sample of 383 were randomly allocated for this study. Of the 383 patients included, 51% were female, age ranges were 18–99 years (mean 51.6). The majority were Australasian Triage scale (ATS) triage category 3 (55%) and 62% had blood tests performed. Blood test performance was found to be associated with advancing age (p < 0.001) but not with department occupancy as determined by the national emergency department overcrowding scale (p = 0.230).ConclusionBlood testing in the emergency department in triaged non-time critical patients was found to be frequent thereby affecting nurses’ already stretched time resource. Older patients were found to be more likely to have a blood test. There is a positive correlation between blood test performance and length of stay in the emergency department.