Background: Peripheral intravenous catheters (PIVCs) serve as crucial devices for essential care administration in emergency departments (ED). In Australia, to standardise clinical practice, the national PIVC Clinical Care Standard was introduced in 2021, however adherence to the Standard has not been adequately explored. Therefore, this study aims to investigate ED clinicians' adherence to the Standard via prospective audit. Method: This cross-sectional observational study of PIVCs was conducted in three Australian EDs between 2022 and 2023. Data were collected in alignment with the quality indicators in the PIVC Clinical Care Standard. Research nurses collected the data from bedside observation and chart audit, with data analysed descriptively. Findings: Out of 1568 episodes of PIVC care recorded, there were notable shortcomings. ED nurses and doctors provided minimal patient partnership during insertion episodes: PIVC self-care education (n = 4, 1.4%), discussion of potential risks/benefits (n = 8, 2.9%), and reporting of concerns (n = 16, 5.8%). Insertions primarily occurred at the antecubital fossa (n = 225, 81.2%), with a common issue being inadequate time for antiseptic solution to air dry (n = 156, 56.3%). Ongoing needs assessment was unable to be assessed due to documentation limitations, which were generally incomplete. Idle catheters (inserted but not used) were prevalent (n = 115, 41.8%), and only a quarter of inpatient ward admissions (n = 75, 27.3%) had clear indications for PIVC use. Conclusion: These findings highlight the suboptimal ED PIVC practices that require attention and improvement. Innovative interventions and technology are necessary to address some of these suboptimal practices due to their complexity and persistent challenges, despite previous efforts by clinicians and researchers. Implications for the Profession and Patient Care: The findings underscore the need for well-resourced efforts to ensure adherence to evidence-based practices in dynamic clinical settings. Reporting Method: The study is reported following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement. Patient or Public Contribution: None.