Background: Given the rising trend of delaying pregnancy to later in life, more women are diagnosed with breast cancer during pregnancy. Management is still controversial and relies on expert guidelines. Thus the experience of single centres with high patients’ volume remains of interest. Methods: All breast cancer patients (pts) diagnosed at the European Institute of Oncology (IEO) in Milan were included in a specific registry since 1995. Results: Out of 8340 patients < 47 y/o registered up to Dec 2012, 167 were diagnosed during pregnancy (2%). Median age was 36 years (24-47y). Median gestational age was 18 weeks (1-38 w). 73 % pts had a pT1-2 tumor, with positive nodes in 48%. 9,6% had luminal A, 38% luminal B, 26% basal like and 16% HER2+ tumors, according to St Gallen criteria. 29/167 pts (17%) opted for an induced abortion. Of the remaining 97 pts, 81 (84%) underwent definitive surgery during pregnancy; 58 (72%) and 23 pts (28%) had quadrantectomy and mastectomy, respectively. Immediate breast reconstruction was performed in 13 cases. Sentinel node procedure (SLN) was performed in 42 pts (52%), with positive axilla in 10 pts. 41 pts (51%) received chemotherapy during pregnancy. Regimens included weekly epirubicin (24 pts), EC/AC (12 pts), FAC/FEC (3 pts), q21 epirubicin (2 pts). No G3-G4 toxicities were reported. No pregnancy complications were observed, with the exception of 1 case of premature delivery at 28 weeks. Median gestational age at delivery was 36 weeks (29-40 w). No major malformations were observed. Gestational age at birth and birth-weight were similar in babies who received chemotherapy in-utero (36 w and 2555g) and in babies who did not receive gestational chemotherapy (37w and 2600g). At a median follow-up of 42 months (range: 1-178 m), all children had normal neurological and physical development with no late adverse effects observed. Conclusions: Managing breast cancer during pregnancy should follow standard practice as in non-pregnant pts. Surgeries like SLN and breast reconstruction were performed with no serious complications. Our results further emphasize the safety of anthracycline-based gestational chemotherapy without major effects on pregnancy course or fetal health.