Background The primary objective of this multicenter post-market study was to compare the cosmetic outcome of triclosan-coated VICRYL* Plus sutures with Chinese silk sutures for skin closure of modified radical mastectomy. A secondary objective was to assess the incidence of surgical site infection (SSI).Methods Patients undergoing modified radical mastectomy were randomly assigned to coated VICRYL* Plus antibacterial (Polyglactin 910) suture or Chinese silk suture. Cosmetic outcomes were evaluated postoperatively at days 12 (±2) and 30 (±5), and the evidence of SSI was assessed at days 3, 5, 7, 12 (±2), 30 (±5), and 90 (±7). Cosmetic outcomes were independently assessed via visual analogue scale (VAS) score evaluations of blinded incision photographs (primary endpoint) and surgeon-assessed modified Hollander Scale (mHCS) scores (secondary endpoint).SSI assessments used both CDC criteria and ASEPSIS scores.Results Six Chinese hospitals randomized 101 women undergoing modified radical mastectomy to closure with coated VICRYL* Plus suture (n=51) or Chinese silk suture (n=50). Mean VAS cosmetic outcome scores for antibacterial suture (67.2) were better than for Chinese silk (45.4) at day 30 (P＜0.0001)). Mean mHCS cosmetic outcome total scores, were also higher for antibacterial suture (5.7) than for Chinese silk (5.0) at day 30 (P=0.002).Conclusions Patients using coated VICRYL* Plus suture had significantly better cosmetic outcomes than those with Chinese silk sutures. Patients using coated VICRYL* Plus suture had a lower SSI incidence compared to the Chinese silk sutures, although the difference did not reach statistical significance. (ClinicalTrials.gov NCT 00768222)