Aim: To determine peripheral intravenous catheter (PIVC) characteristics, complications and risk factors among patients in cancer units. Methods: A secondary analysis of a global, cross-sectional study (127 hospitals in 24 countries). Participants (≥18 years) admitted to cancer units were assessed once for PIVC characteristics and the presence of complications. Variables included patient demographics, device characteristics, treatment details, and device and/or site complications. PIVC characteristics were presented using qualitative descriptors; mixed-effects logistic regression models determined risk factors for PIVC complications. Results: In total, 1,807 participants (1,812 PIVCs) were included; 12% (n=215) of PIVCs presented with complications. Risk factors included: insertion by doctors; insertion in ED and ambulance/other locations; poor PIVC dressing integrity; dwell time ≥49 hours; and administration of colloids/blood products and antiemetics. Conclusions: At least one in ten PIVCs in cancer units present with complications; regular PIVC assessment and improved dressing integrity is likely to reduce risk and improve outcomes.