ObjectivesAlthough it is the most performed invasive procedure, peripheral intravenous catheter (PIVC) insertion in children can be difficult. The primary objective of the study was to identify the factors associated with difficult intravenous access (DIVA) in the paediatric ED, including patient, proceduralist and situational factors.MethodsThis was a single‐centre prospective observational cohort study conducted over 28 consecutive days. Research assistants observed PIVC insertion attempts for children under 16 years of age and recorded data for variables relating to the patient, proceduralist and event. Univariate logistic regression modelling was performed to identify factors associated with DIVA, defined as unsuccessful PIVC insertion on the first attempt.ResultsA total of 134 participants were recruited; 66 were male (49%) with a median age of 5.7 years. Fifty‐two (39%) were classified as having DIVA. There was a total of 207 PIVC insertion attempts with two or more attempts needed for 48 children (36%). Patient factors associated with DIVA included age of 3 years or less and limited vein options. Proceduralist factors included gestalt of 50% or less chance of success, use of a larger gauge (smaller bore) PIVC and less PIVC insertion experience. Situational factors included a combative child, higher pain score and loud ambient noise.ConclusionsThe present study identified multiple patient, proceduralist and situational factors that were associated with DIVA in the paediatric ED. Future studies should explore the development and implementation of a package to address DIVA in children, with the patient‐centred goals of reducing pain and improving success.