We retrospectively analyzed 232 patients affected by well differentiated ductal intraepithelial neoplasia (DIN1c or DCIS G1) treated with conservative surgery without adjuvant radiotherapy.25 invasive and 18 non-invasive local recurrences were observed (median follow-up 80 months; 5-year cumulative incidence: 12.2%). Seven of the 15 young patients (<40 y) developed local recurrence (2 in situ, 5 invasive). Age <50 (HR 1.89, 95% C.I. 1.01–3.45), multifocality (HR 3.21, 95% C.I. 1.46–7.06), Ki-67 > 7% (HR 2.33, 95% C.I. 1.20–4.55) and surgical margins <10 mm (HR 2.00, 95% C.I. 1.06–3.76) were significantly associated with an increased risk of local recurrence.Young age, multifocality and small margins appeared as clear risk factors of local recurrence in DIN1c (DCIS G1) population. The presence of multiple poor prognostic features warrant a thorough discussion regarding local treatment.