Poor wound healing is one of the most common complications after laparotomy, especially in lower abdominal midline incisions. The aims of this trial are to assess the value of subcutaneous suture and identify risk factors to prevent poor wound healing. From October 2010 to October 2011, a total of 180 patients were randomized to the subcutaneous suture group (n = 89) or control group (n = 91) after laparotomy with a lower midline incision. Univariate and multivariate analyses were performed to determine the predictive significance of variables of poor wound healing. Patients' demographics, preoperative laboratory values, and operative details were comparable between the two groups. The overall rate of poor wound healing was 16.7 per cent (30 of 180). Patients randomized to subcutaneous suture group (n = 89) had poor healing in 10.1 per cent (nine of 89) and those without suture (n = 91) in 23.1 per cent (21 of 91) (P = 0.020). Multivariate logistic regression analysis revealed that American Society of Anesthesiologists (ASA) score (3 to 4) (odds ratio [OR], 2.933), subcutaneous suture (OR, 0.323), and blood loss (greater than 200 mL) (OR, 5.995) were independent risk factors for poor wound healing. Subcutaneous suture can effectively accelerate wound healing. Nonsubcutaneous suture, ASA score (3 to 4), and blood loss (greater than 200 mL) are independent risk factors for poor would healing.