BACKGROUND Recurrent periductal mastitis (PDM) is usually refractory to medical treatment and normally requires surgical intervention or even mastectomy. This study aimed to evaluate the effectiveness and safety of extended excision with transferring a random breast dermo-glandular flap (BDGF) in the treatment of severe PDM. METHODS Between January 2010 and December 2011, 47 patients with recurrent PDM were consecutively and prospectively hospitalized for elective extended excision. A random BDGF was harvested from the ipsilateral breast tissue overlying the pectoralis major muscle and transferred to resurface the breast tissue defect. The donor site wound was closed using interrupted sutures. Main outcome measures included flap survivability, surgical morbidities, and follow-up cosmetic outcome. RESULTS All flaps survived uneventfully and all wounds healed by primary intention. PDM recurred in two patients (2/47, 4.3%) and required second-look surgery. The cosmetic outcome was self-evaluated to be excellent in 31.9% (15/47) of patients, good in 36.2% (17/47), acceptable in 21.3% (10/47), and poor in 10.6% (5/47), respectively. The donor site wounds healed uneventfully with minimal scarring. CONCLUSIONS Extended excision with transferring BDGF is an effective, safe treatment modality for recurrent PDM with a low-risk morbidity and favorable cosmesis.