BACKGROUND/PURPOSE: Arterial catheter complications are a common problem in a pediatric critical care setting, but reported complication rates and risk factors associated with peripheral arterial catheter complications vary. We conducted a retrospective cohort study to identify risk factors in a pediatric patient population. METHODS: We performed a detailed abstraction of provider notes in the electronic medical records of inpatients =18years of age who underwent arterial line placement between January 1, 2008 and January 1, 2013 at a university-affiliated standalone pediatric hospital. Inpatient records were assessed for complications associated with arterial catheterization and risk factors inherent to arterial catheter insertion. RESULTS: Two hundred twenty-eight children were identified, of whom 75 (33%) had a total of 106 arterial catheter complications. Complications included line malfunctions (59%, n=63), bleeding (16%, n=17), multiple complications (11%, n=12), infiltration (8%, n=9), and hematoma (4%, n=4). Line malfunction was reported in all patients with multiple complications. Independent predictors of complications associated with arterial catheterization were the presence of more than one provider during the insertion (p=0.007) and insertion attempts at multiple sites (p=0.036). CONCLUSIONS: Our analysis suggests the need for a prospective study to comprehensively assess provider-related risk factors associated with arterial catheter complications in children. LEVEL OF EVIDENCE: IV.