Background: Urinary catheters are placed after rectal surgery to prevent urinary retention, but prolonged use may increase the risk of urinary tract infection (UTI). This review evaluated the non-inferiority of early urinary catheter removal compared with late removal for acute urinary retention risk after rectal surgery. Methods: MEDLINE, Embase and the Cochrane Central Register of Controlled Trials were searched from January 1980 to February 2019. RCTs comparing early versus late catheter removal after rectal surgery were eligible. Primary outcomes were acute urinary retention and UTI; the secondary outcome was length of hospital stay. Early catheter removal was defined as removal up to 2 days after surgery, with late removal after postoperative day 2. The non-inferiority margin from an included trial was used for analysis of change in urinary retention (ΔNI = 15 per cent). Pooled estimates of risk differences (RDs) were derived from random-effects models. Risk of bias was assessed using a modified Cochrane risk-of-bias tool. Results: Four trials were included, consisting of 409 patients. There was insufficient evidence to conclude non-inferiority of early versus late catheter removal for acute urinary retention (RD 9 (90 per cent c.i. −1 to 19) per cent; PNI = 0·31). Early catheter removal was superior for UTI (RD −11 (95 per cent c.i. −17 to −4) per cent; P = 0·001). Results for length of stay were mixed. There were insufficient data to conduct subgroup analyses. Conclusion: The existing literature is inconclusive for non-inferiority of early versus late urinary catheter removal for acute urinary retention. Early catheter removal is superior in terms of reducing the risk of UTI.