Objectives: To examine variation in practice and adherence to international clinical guidelines for the management of fever among Australian Emergency Department (ED) clinicians. Methods: Cross-sectional survey across 22 Australian EDs. Clinical vignettes were used to determine compliance with international best practice guidelines (use of antipyretic monotherapy to alleviate fever-associated child distress) for paediatric fever treatment. Comparisons were made between specialist paediatric EDs and general (non-specialist paediatric) EDs, and between medical and nursing staff. Results: Of 539 survey respondents (300 doctors, 239 nurses; overall response rate 65.9%), only 9.3% (50/539, 95% confidence interval [CI] 7.1%–12.0%) adhered to evidence-based practice guidelines. Specialist paediatric ED clinicians demonstrated less than half the adherence of those from general EDs (5.4% [11/204] vs. 12.4% [38/307], difference −7.0%, 95% CI −11.7% to −1.9%). In a febrile settled child with normal hydration, the proportion of respondents who opted for antipyretics more than doubled in the context of elevated vital signs (40.4% [218/539] vs. 83.1% [44/539], difference −42.7%, 95% CI −46.8% to −38.2%). Nearly half of respondents (239/539, 46.8%, 95% CI 42.4%–51.2%) endorsed giving combined antipyretic therapy. In a febrile settled child, most participants would give antipyretics for temperature reduction (453/539, 84.0%, 95% CI 80.7%–86.9%) and for decreased fluid intake (468/539, 87.5%, 95% CI 84.4%–90.0%). Over one-third (192/539, 36.0%, 95% CI 32.1%–40.2%) recommended using antipyretics for febrile convulsion prevention during the current illness. Conclusions: Fewer than 10% of Australian ED clinicians self-report practice consistent with international consensus recommendations for paediatric fever management.