Objective To evaluate clinical efficacy and safety of single puncture and irrigation with Mammotome system in treatment of lactational breast abscess without drainage. Methods 32 patients with lacta-tional breast abscess were treated with ultrasound-guided puncture and irrigation by Mammotome system. Pus was cleared and necrotic material was removed. The residual cavity was irrigated with 3% hydrogen peroxide solution and Kangfuxin solution and no drainage was placed. Breast-feeding on time was encouraged. Results All pa-tients were successfully treated with single puncture and irrigation. The average length of hospital stay was 4 days. Except for 3 cases actively requesting to stop lactating, the other 29 patients continued to breast-feed. There was one case with postoperative hematoma, one with wound granuloma, and no other complications occurred. There was no relapse during the follow-up of 3 to 36 months. All patients were satisfied with the appearance of the breasts. Conclusions Single puncture and irrigation with Mammotome system without drain placement is a safe procedure in treatment of lactational breast abscess with the advantage of minimal invasion, low complication and does not affect breastfeeding.