Based on 31 root cause analysis reports of surgical incidents in Australia, this study found that the most commonly retained surgical items were surgical packs (n=9) and drain tubes (n=8). While most retained items were detected on the day of the procedure (n=7), about 16% of items were detected 6-months or later post-procedure. The study found that complex or lengthy procedures were more likely to lead to a retained item, and many retained items, such as drains or catheters, occur in postoperative settings where surgical counts are not applicable.