Groin wound infections in patients undergoing vascular procedures often cause a lengthy process of wound healing. Several clinical studies and case reports show a reduction of surgical site infections (SSIs) in various wound types after using closed incision negative pressure therapy (ciNPT). The aim of this prospective, randomised, single‐institution study was to investigate the effectiveness of ciNPT (PREVENA™ Therapy) compared to conventional therapy on groin incisions after vascular surgery. From 1 February to 30 October 2015, 100 patients with 129 groin incisions were analysed. Patients were randomised and treated with either ciNPT (n = 58 groins) or the control dressing (n = 71 groins). ciNPT was applied intraoperatively and removed on days 5–7 postoperatively. The control group received a conventional adhesive plaster. Wound evaluation based on the Szilagyi classification took place postoperatively on days 5–7 and 30. Compared to the control group, the ciNPT group showed a significant reduction in wound complications (P < 0·0005) after both wound evaluation periods and in revision surgeries (P = 0·022) until 30 days postoperatively. Subgroup analysis revealed that ciNPT had a significant effect on almost all examined risk factors for wound healing. ciNPT significantly reduced the incidence of incision complications and revision procedures after vascular surgery.