Objectives: To investigate the burden of peripheral intravenous catheters (PIVCs) in older hospitalised patients. Methods: A cross-sectional prospective observational study (2014/2015) to describe the characteristics, indications and outcomes of PIVCs among patients aged ≥65 from 65 Australian hospitals. Results: Amongst 2179 individual PIVCs (in 2041 patients, mean age 77.6 years, 45% female, 58% in NSW), 43% were inserted by doctors and 74% used that day, meaning 25% were ‘idle’. Overall, 18% (393/2179) exhibited signs of PIVC-related complications. Most commonly exhibited PIVC-related complications were tenderness (4.1%) and local redness (1.8%). Nearly one in three (29.1%) dressings was soiled, loosened or had come off, and only 36.8% had the time and date documented on the dressing. Both infusing IV medications (aOR 1.74, 95% CI 1.28–2.38, p < 0.001) and inserting the PIVC in a non-upper limb vein (aOR 3.40 compared to forearm [reference site], 95% CI 1.62–7.17, p < 0.001) were independently associated with PIVC failure. Phlebitis was exhibited in 7% (154) of the patients. Only infusing intravenous medications increased the likelihood of developing symptoms of phlebitis (aOR 1.61, 95% CI 1.01–2.57, p = 0.05). Increasing age was inversely associated with symptoms of phlebitis. Among the 1575 patients (79%) who rated their PIVC experience using the Likert scale 0–10 (where 10 = ‘best possible’), the median score was 8 (IQR 6–10). Age in highest quartile (>84 years) was independently associated with lower likelihood of a high score (aOR 0.71, 95% CI 0.54–0.94, p = 0.02). Conclusions: Given 1 in 5 PIVCs were identified with having complications, further research should focus on optimising PIVC use in older patients.