Stoma reversal carries a risk of surgical site infection (SSI). Purse-string approximation (PSA) has been reported as an attractive alternative to conventional primary wound closure for stoma reversal, but its efficacy is still under debate. Patients undergoing elective stoma reversal were randomized to undergo PSA or primary closure with a drain (PCD). All patients received preoperative bowel cleansing and antimicrobial prophylaxis. The primary endpoint was the incidence of wound healing at the stoma site 30 days after surgery. The secondary endpoint was the 30-day SSI rate after surgery. A total of 159 patients (PCD group, n = 79; PSA group, n = 80) were eligible for this study. The incidence of wound healing at the stoma site was 92.4% in the PCD group and 62.5% in the PSA group [difference (95% confidence interval − 29.9% (− 42.9 to − 16.9%)]. The 30-day SSI rate at the stoma site, as the secondary endpoint, was 8.9% in the PCD group and 5.0% in the PSA group (P = 0.35). These results suggest that PCD may remain the standard procedure for stoma reversal surgery.